The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
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COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3M Co. COM 88579Y101 1,094 10,000 SH   SOLE 0 10,000 0 0
Altria Group Inc. COM 02209S103 701 20,048 SH   SOLE 0 20,048 0 0
AmerisourceBergen Corp. COM 03073E105 88,372 1,582,870 SH   SOLE 0 1,566,680 0 16,190
Apple Inc. COM 037833100 105,973 267,555 SH   SOLE 0 264,756 0 2,799
Arbitron Inc. COM 03875Q108 19,949 429,475 SH   SOLE 0 308,101 0 121,374
Ares Capital Corp. COM 04010L103 68,813 4,000,734 SH   SOLE 0 2,674,822 0 1,325,912
Argo Group International Holdings Ltd. COM 002499543 5,027 118,594 SH   SOLE 0 116,394 0 2,200
Arthur J. Gallagher & Co. COM 363576109 67,850 1,552,983 SH   SOLE 0 1,027,293 0 525,690
Bank of Montreal COM 063671101 870 15,000 SH   SOLE 0 15,000 0 0
Bank of Nova Scotia COM 064149107 164,621 3,079,671 SH   SOLE 0 3,045,080 0 34,591
Barrick Gold Corp. COM 067901108 578 36,600 SH   SOLE 0 36,600 0 0
Baxter International Inc. COM 071813109 76,071 1,098,175 SH   SOLE 0 1,086,218 0 11,957
BB&T Corp. COM 054937107 101,663 3,000,687 SH   SOLE 0 2,967,762 0 32,925
Becton, Dickinson and Co. COM 075887109 75,659 765,551 SH   SOLE 0 757,715 0 7,836
Berkshire Hathaway Inc. CL A 084670108 45,016 267 SH   SOLE 0 265 0 2
Berkshire Hathaway Inc. CL B 084670702 4,950 44,231 SH   SOLE 0 40,217 0 4,014
Brookfield Infrastructure Partners LP COM G16252101 17,893 490,338 SH   SOLE 0 439,837 0 50,501
Brown & Brown Inc. COM 115236101 55,571 1,723,651 SH   SOLE 0 1,139,565 0 584,086
Canadian National Railway Co. COM 136375102 129,893 1,334,126 SH   SOLE 0 1,322,126 0 12,000
Canadian Natural Resources Ltd. COM 136385101 164,460 5,833,732 SH   SOLE 0 5,818,664 0 15,068
CARBO Ceramics Inc. COM 140781105 39,775 589,878 SH   SOLE 0 408,705 0 181,173
CareFusion Corp. COM 14170T101 19,629 532,665 SH   SOLE 0 527,821 0 4,844
CBIZ Inc. COM 124805102 6,751 1,006,152 SH   SOLE 0 688,999 0 317,153
Cenovus Energy Inc. COM 15135U109 182,810 6,409,000 SH   SOLE 0 6,391,450 0 17,550
Cisco Systems Inc. COM 17275R102 107,502 4,422,138 SH   SOLE 0 4,374,559 0 47,579
Citigroup Inc. COM 172967424 1,199 25,000 SH   SOLE 0 25,000 0 0
Coca-Cola Femsa S.A.B. de C.V. SPONSORED ADR 191241108 4,936 35,183 SH   SOLE 0 35,183 0 0
Corporate Executive Board Co. COM 21988R102 59,177 936,048 SH   SOLE 0 612,524 0 323,524
DeVry Inc. COM 251893103 72,497 2,337,105 SH   SOLE 0 1,599,908 0 737,197
Diageo PLC SPONSORED ADR 25243Q205 544 4,736 SH   SOLE 0 4,736 0 0
Dun & Bradstreet Corp. COM 26483E104 2,517 25,830 SH   SOLE 0 25,364 0 466
Eaton Vance Variable Rate Income Trust COM 278279104 8,724 526,490 SH   SOLE 0 526,490 0 0
Emerson Electric Co. COM 291011104 67,637 1,240,138 SH   SOLE 0 1,227,087 0 13,051
Enbridge Inc. COM 29250N105 438 10,421 SH   SOLE 0 10,421 0 0
EnCana Corp. COM 292505104 1,625 96,077 SH   SOLE 0 96,077 0 0
Entercom Communications Corp. CL A 293639100 5,828 617,377 SH   SOLE 0 617,377 0 0
Equifax Inc. COM 294429105 160,014 2,715,329 SH   SOLE 0 2,265,239 0 450,090
Expedia Inc. COM 30212P303 45,050 748,955 SH   SOLE 0 525,858 0 223,097
Federated Investors Inc. CL B 314211103 44,588 1,626,690 SH   SOLE 0 1,122,605 0 504,085
FirstService Corp. SUB VTG SH 33761N109 5,801 185,000 SH   SOLE 0 185,000 0 0
FXCM Inc. CL A 302693106 66,413 4,047,118 SH   SOLE 0 2,727,469 0 1,319,649
General Electric Co. COM 369604103 1,160 50,000 SH   SOLE 0 50,000 0 0
Gentex Corp. COM 371901109 63,328 2,747,423 SH   SOLE 0 1,844,846 0 902,577
Gladstone Investment Corp. COM 376546107 19,449 2,646,169 SH   SOLE 0 1,729,346 0 916,823
GlaxoSmithKline PLC SPONSORED ADR 37733W105 443 8,867 SH   SOLE 0 8,867 0 0
Google Inc. CL A 38259P508 63,822 72,494 SH   SOLE 0 71,726 0 768
Graco Inc. COM 384109104 34,229 541,505 SH   SOLE 0 363,341 0 178,164
Grupo Televisa S.A. SPONSORED ADR 40049J206 3,916 157,664 SH   SOLE 0 157,664 0 0
HCC Insurance Holdings Inc. COM 404132102 45,533 1,056,199 SH   SOLE 0 650,325 0 405,874
Hilltop Holdings Inc. COM 432748101 77,517 4,726,627 SH   SOLE 0 3,032,438 0 1,694,189
Home Depot Inc. COM 437076102 387 5,000 SH   SOLE 0 5,000 0 0
Humana Inc. COM 444859102 90,232 1,069,352 SH   SOLE 0 1,058,610 0 10,742
Imperial Oil Ltd. COM 453038408 74,581 1,953,683 SH   SOLE 0 1,948,183 0 5,500
Jacobs Engineering Group Inc. COM 469814107 46,590 845,096 SH   SOLE 0 834,044 0 11,052
Johnson & Johnson Inc. COM 478160104 136,738 1,592,574 SH   SOLE 0 1,576,531 0 16,043
JTH Holding Inc. CL A 46637N103 253 15,586 SH   SOLE 0 15,586 0 0
Kayne Anderson Energy Development Co. COM 48660Q102 23,846 928,582 SH   SOLE 0 609,323 0 319,259
Kraft Foods Group Inc. COM 50076Q106 279 5,000 SH   SOLE 0 5,000 0 0
Laboratory Corporation of America Holdings COM 50540R409 2,728 27,256 SH   SOLE 0 26,773 0 483
Leucadia National Corp. COM 527288104 84,147 3,209,250 SH   SOLE 0 2,662,260 0 546,990
LoJack Corp. COM 539451104 717 227,708 SH   SOLE 0 227,708 0 0
Lorillard Inc. COM 544147101 79,119 1,811,341 SH   SOLE 0 1,791,149 0 20,192
M&T Bank Corp. COM 55261F104 240 2,148 SH   SOLE 0 2,148 0 0
Madison Square Garden Co. COM 55826P100 42,813 722,580 SH   SOLE 0 504,617 0 217,963
MarketAxess Holdings Inc. COM 57060D108 104,154 2,227,884 SH   SOLE 0 1,487,655 0 740,229
McCormick & Co., Inc. COM 579780206 3,679 52,294 SH   SOLE 0 52,294 0 0
McDonald's Corp. COM 580135101 2,238 22,607 SH   SOLE 0 22,607 0 0
McEwen Mining Inc. COM 58039P107 18 11,000 SH   SOLE 0 11,000 0 0
Merck & Co., Inc. COM 58933Y105 1,282 27,594 SH   SOLE 0 27,594 0 0
MICROS Systems Inc. COM 594901100 41,525 962,333 SH   SOLE 0 685,378 0 276,955
Microsoft Corp. COM 594918104 75,707 2,192,495 SH   SOLE 0 2,171,327 0 21,168
Mondelez International Inc. COM 609207105 428 15,000 SH   SOLE 0 15,000 0 0
Moody's Corp. COM 615369105 4,004 65,720 SH   SOLE 0 64,546 0 1,174
Morgan Stanley COM 617446448 481 19,694 SH   SOLE 0 19,694 0 0
MSC Industrial Direct Co., Inc. COM 553530106 29,659 382,892 SH   SOLE 0 251,231 0 131,661
MSCI Inc. COM 55354G100 57,641 1,732,514 SH   SOLE 0 1,190,951 0 541,563
NGP Capital Resources Co. COM 62912R107 3,992 651,147 SH   SOLE 0 423,070 0 228,077
Northern Trust Corp. COM 665859104 81,891 1,414,348 SH   SOLE 0 1,400,189 0 14,159
Novartis AG SPONSORED ADR 66987V109 570 8,060 SH   SOLE 0 8,060 0 0
Nutraceutical International Corp. COM 67060Y101 21,907 1,071,761 SH   SOLE 0 694,108 0 377,653
Occidental Petroleum Corp. COM 674599105 104,408 1,170,100 SH   SOLE 0 1,157,534 0 12,566
Oracle Corp. COM 68389X105 97,746 3,181,839 SH   SOLE 0 3,147,108 0 34,731
Penske Auto Group Inc. COM 70959W103 67,303 2,203,756 SH   SOLE 0 1,452,192 0 751,564
PepsiCo Inc. COM 713448108 84,265 1,030,261 SH   SOLE 0 1,019,608 0 10,653
Pfizer Inc. COM 717081103 653 23,329 SH   SOLE 0 23,329 0 0
Philip Morris International Inc. COM 718172109 85,464 986,660 SH   SOLE 0 976,020 0 10,640
Potash Corporation of Saskatchewan Inc. COM 73755L107 1,381 36,200 SH   SOLE 0 36,200 0 0
Primerica Inc. COM 74164M108 75,265 2,010,286 SH   SOLE 0 1,394,327 0 615,959
Procter & Gamble Co. COM 742718109 64,833 842,096 SH   SOLE 0 833,544 0 8,552
Qualcomm Inc. COM 747525103 78,853 1,290,979 SH   SOLE 0 1,277,354 0 13,625
Ritchie Bros. Auctioneers Inc. COM 767744105 176,900 9,203,974 SH   SOLE 0 9,132,723 0 71,251
Rogers Communications Inc. CL B 775109200 75,620 1,930,416 SH   SOLE 0 1,904,576 0 25,840
Royal Bank of Canada COM 780087102 162,094 2,782,004 SH   SOLE 0 2,749,004 0 33,000
Shaw Communications Inc. CL B 82028K200 145,109 6,046,649 SH   SOLE 0 5,999,649 0 47,000
Solera Holdings Inc. COM 83421A104 34,182 614,230 SH   SOLE 0 407,926 0 206,304
SS&C Technologies Holdings Inc. COM 78467J100 20,808 632,466 SH   SOLE 0 466,282 0 166,184
Strayer Education Inc. COM 863236105 22,375 458,224 SH   SOLE 0 349,639 0 108,585
Synnex Corp. COM 87162W100 45,095 1,066,574 SH   SOLE 0 741,031 0 325,543
Talisman Energy Inc. COM 87425E103 132 11,600 SH   SOLE 0 11,600 0 0
Tech Data Corp. COM 878237106 44,351 941,834 SH   SOLE 0 583,652 0 358,182
Teleflex Inc. COM 879369106 43,204 557,546 SH   SOLE 0 378,496 0 179,050
TeleTech Holdings Inc. COM 879939106 3,444 146,976 SH   SOLE 0 144,268 0 2,708
Thomson Reuters Corp. COM 884903105 182,094 5,580,328 SH   SOLE 0 5,538,342 0 41,986
Tim Hortons Inc. COM 88706M103 140,610 2,599,965 SH   SOLE 0 2,574,165 0 25,800
Toronto-Dominion Bank COM 891160509 155,287 1,933,493 SH   SOLE 0 1,909,970 0 23,523
Tronox Ltd. CL A Q9235V101 26,212 1,300,867 SH   SOLE 0 1,182,711 0 118,156
U.S. Concrete Inc. COM 90333L201 298 18,161 SH   SOLE 0 18,161 0 0
Union Pacific Corp. COM 907818108 91,170 590,937 SH   SOLE 0 584,446 0 6,491
United Technologies Corp. COM 913017109 88,923 956,776 SH   SOLE 0 946,178 0 10,598
Valassis Communications Inc. COM 918866104 57,236 2,327,620 SH   SOLE 0 1,614,289 0 713,331
Visa Inc. COM 92826C839 74,099 405,464 SH   SOLE 0 401,149 0 4,315
Walgreen Co. COM 931422109 45,217 1,023,004 SH   SOLE 0 1,012,303 0 10,701
Wal-Mart Stores Inc. COM 931142103 745 10,000 SH   SOLE 0 10,000 0 0
Weight Watchers International Inc. COM 948626106 42,140 916,079 SH   SOLE 0 638,443 0 277,636
Western Union Co. COM 959802109 111,269 6,503,133 SH   SOLE 0 6,437,394 0 65,739