1995, 1996 and 1997 Mint Set Trio. In 1995, only 1,038,787 were issued by the U.S. Mint; it would boast the lowest mint set production since 1964 until 1997's set was released.
As an experiment in 1996, a regular U.S. Brilliant Uncirculated dime was planned with the distinctive W mintmark; however, it was issued only in this mint set, whose mintage ended at just 1.5 million. Since none entered commerce, this W dime is especially coveted. Prior to this, the U.S. branch mint at West Point had previously struck only some modern commemoratives and silver and gold eagles.
Just 950,473 mint sets were issued in 1997, the lowest output for U.S. mint sets in the span 1964-2003, encompassing 40 years of issue. It's one of the key scarcities of the series in recent decades.