Total immigration to Canada, 1979-2004 - numbers of people granted permanent residence in Canada with breakdown for various refugee categories
IRB, Refugee Protection Division, 2004
Detention Statistics in Canada for 2002 html version pdf version
Detention Statistics in Canada for 2003 year to date html version
Useful sources of statistics on refugees (for Canada and other countries):
US Committee for Refugees, World Refugee Survey 2004
Citizenship and Immigration Canada also has some statistical information on its site.