When the U.S. Mint introduced special commemorative coins in the early 1980s, they were sold individually and as part of Prestige Proof Sets. Most collectors bought their commemorative proofs individually, and most proof set buyers continued to acquire regular sets each year. The result is that Prestige Proof Sets have become BY FAR the scarcest form of these coins. The 506,126 mintage for the 1990 Prestige Proof Set was about 18% of the regular proof set's that year. The 1990 Prestige Proof Set contains the five regular annual issues as well as the commemorative Eisenhower Centennial silver dollar in finest-quality proof form.