1970-1989 2 Decades Proof Set Run - 110 Coins, 20 Complete Sets. 1970-1989 2 Decades Proof Set Run - 110 Coins, 10 Complete Sets. Includes All Ike $1 Years. Both the 1975 and 1976 proof sets contained the Bicentennial quarters, half dollars, and dollars featuring the double date 1776–1976. This was due to the fact that the mint did not produce those coins dated 1975, and the bicentennial coins were produced both years.