Based on the chart I separate my Canadians in 3 main categories. 1942-1979 (3.24g, 98%cu), 1980-1981 (2.8g, 98% cu) and 1982-1996 (2.5g, 98% cu). The 1997-present gets sent back into the wild. Here in the south I average 3 Canadian Cu per 50 rolls.
Composition throughout history (Canadian) * source: Wikipedia
Years Mass Diameter/Shape Composition[12]
2000–present 2.35 g 19.05 mm, round 94% steel, 1.5% nickel, 4.5% copper plated zinc
1997–1999 2.25 g 19.05 mm, round 98.4% zinc, 1.6% copper plating
1982–1996 2.5 g 19.1 mm, 12-sided 98% copper, 1.75% tin, 0.25% zinc
1980–1981 2.8 g 19.0 mm, round 98% copper, 1.75% tin, 0.25% zinc
1978–1979 3.24 g 19.05 mm, round 98% copper, 1.75% tin, 0.25% zinc
1942–1977 3.24 g 19.05 mm, round 98% copper, 0.5% tin, 1.5% zinc
1920–1941 3.24 g 19.05 mm, round 95.5% copper, 3% tin, 1.5% zinc
1876–1920 5.67 g 25.4 mm, round 95.5% copper, 3% tin, 1.5% zinc
1858–1859 4.54 g 25.4 mm, round 95% copper, 4% tin, 1% zinc