The 2003 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