1970, 1990 & 2000 Proof Set Trio. The 1970 proof set had a total mintage of merely 2.6 million and contained the last 40% silver Kennedy half dollar in its finest form. Just 2.8 million proof sets were produced in 1990 and even less exist intact today as many were broken up to harvest the year's Kennedy half dollar. The Sacagawea dollar debuted in the 2000 proof set along with five commemorative State quarters from the second year of the series. For the first time, a U.S. proof set contained 10 coins: the cent, nickel, dime, half dollar, dollar and all five of the second year commemorative state quarters.
2002, 2005 & 2008 Mint Set Trio. In 2002, the 20-coin mint set had an output of 1.1 million, which was less than half the mintage of the year's proof set. In 2005, the mint set had grown to include 22 coins and produced slightly more than a million sets. This was the first year that the U.S. Mint introduced a special satin finish that would become the standard finish for its Uncirculated sets. After 2005, mint set outputs began to dwindle. Just 745,464 were produced in 2008, but those sets contained a whopping 28 coins! In addition to Philadelphia and Denver cents, nickels, dimes and half dollars they include the year's commemorative State quarters, Sacagawea and Presidential dollars.