According to data from https://economicdashboard.alberta.ca/ (US visitors by vehicle dataset), the number of American vehicles entering Canada by land through the Del Bonita border crossing in December was:

1996: 357
1997: 566
1998: 605
1999: 718
2000: 626
2001: 730
2002: 568
2003: 531
2004: 421
2005: 350
2006: 285