The 2001 CIA World Factbook

by United States. Central Intelligence Agency

Canada:
18 years of age; universal

Cape Verde:
18 years of age; universal

Cayman Islands:
18 years of age; universal

Central African Republic:
21 years of age; universal

Chad:
18 years of age; universal

Chile:
18 years of age; universal and compulsory

China:
18 years of age; universal

Cocos (Keeling) Islands:
NA

Colombia:
18 years of age; universal

Comoros:
18 years of age; universal