Just 2.8 million of this start-of-decade proof set ever existed, far below the maximum 4.1 million mintage of 1976. The set contains finest-quality proofs of the cent through half dollar denominations, with deep-struck frosted engravings and mirror fields. These proof coins were issued only as part of a complete denomination set. To satisfy demand for individual Kennedy half dollar proofs, dealers had to break up some existing 1990 proof sets. So even fewer remain in the perfectly intact form we're offering.