Since 1946 the Roosevelt dime has been minted every year. Through 1955, all three mints, Philadelphia, Denver, and San Francisco produced circulating coinage; production at San Francisco ended in 1955, resuming in 1968 with proof coinage only. Through 1964 "D" and "S" mintmarks can be found to the left of the torch. From 1968, the mintmarks have appeared above the date. None were used in 1965–67, and Philadelphia did not show a mintmark until 1980 (in 1982, an error left the "P" off a small number of dimes, which are now valuable). To commemorate the 50th anniversary of the design, the 1996 mint sets included a "W" mintmarked dime made at the West Point Mint. A total of 1,457,000 dimes were issued in the sets, making it the lowest mintage Roosevelt dime up to that time. Since then, the "P" mint mark 2015 reverse proof dime and "W" mint mark 2015 proof dime, minted at Philadelphia and West Point for inclusion in the March of Dimes collector set, have the lowest mintages with 75,000 pieces struck for each.