I'm Canadian so I would let my American friends tell you. Silver was discontinued out of Canadian circulation coins after 1968. From what I heard, a lot of 1967, 1966, 1965 etc 80% silver coinage were hoarded by collectors and coin shops. Since then only commemorative coins were produced in silver until bullion coins came out in 1986.
I think Carmen San Diego was last rumored to be in Singapore, don't know why, just saying.