In 1997, the U.S. Mint issued just 1,975,000 proof sets. That year proved to be the second-lowest regular proof set production in four decades and just 47% of the peak 4.1 million mintage of 1976. Included are superlative proofs of the date's cent, nickel, dime, quarter and half dollar (circulation mintages were up to a thousand times higher). The transparent plastic case protects the exquisite beauty of each proof coin.