Statistics Canada: Canadian Statistics menu: Culture, leisure and travel: Average hours per week of television viewing:
http://www.statcan.ca/english/Pgdb/arts22a.htm

You may also find the following web sites interesting:

Media Awareness Network:
http://www.media-awareness.ca/
Includes data on television, movies and computer games.

Finally look at Trends in the Health of Canadian Youth: http://www.hc-sc.gc.ca/english/media/releases/1999/99118ebk3.htm

It includes information on television, videos and computer games.