Question: What attracted, part of the Nevada State Museum, minted coins for over 21 different years?

Context paragraphs:
Shooting thaler: A shooting thaler ( ; German: "Schützentaler" , French: "Écu de tir" ) is a commemorative coin minted to commemorate one of the Schützenfest (French: "Fête de tir") or free shooting (German: "Freischiessen", French: "Tir libre") tournaments held in various cantons within the Swiss Confederation.  Most of the designs differ from their circulating counterparts, though the pieces issued for the shooting festivals in Geneva in 1851 and Solothurn in 1855 are exceptions.  Most shooting thaler designs depict strongly cantonal or patriotic themes, such as historical military leaders or heraldry.  The entire series can be distinguished from shooting medals by their adherence to the specifications of circulating coinage.  All but the Stans and St. Gallen issues are denominated.  Other countries have minted coins in honor of shooting festivals or marksmanship competitions, but only Swiss pieces are considered shooting thalers.

Nevada State Museum, Las Vegas: The Nevada State Museum, Las Vegas located at the Springs Preserve, in Las Vegas, Nevada is one of 7 Nevada State Museums operated by the Nevada Department of Tourism and Cultural Affairs.  The name was changed from the Nevada State Museum and Historical Society in 2008 when the museum moved from Lorenzi Park in Las Vegas to the Springs Preserve campus.  The museum houses items from the development of Las Vegas as well as the natural history of the area.  The museum is open Tuesday through Sunday, 9 am to 5 pm, closed Thanksgiving and Christmas.

Half sen coin: The half sen coin (半銭 ) was a Japanese coin worth one two-hundredth of a Japanese yen, as 100 "sen" equalled 1 yen.  These coins were minted from 1870 to 1888, but another denomination which had the same value was later minted for a brief period in the late 1910s.  All half sen coins were minted during the Meiji period, and are made from nearly pure copper.  Two different varieties exist for the half sen coin in regard to the dragon featured on the reverse side of the coin.  One variety has "V scales", while the other design shows "square scales" with the latter being more scarce.  The mintage figures shown on the table are in thousands of coins.

Commemorative coins of Australia: Coins of the Australian dollar are circulated with different designs depicting various anniversaries or significant Australian events, these differing coin designs being labelled Australian commemorative coins.  Typically, only the 20c, 50c and $1 coins have been minted in commemoration, however in 2012 a commemorative $2 coin was minted for Remembrance Day and in 2016 a 25c gold coin was minted for Anzac Day.

2 euro commemorative coins: €2 commemorative coins are special euro coins minted and issued by member states of the eurozone since 2004 as legal tender in all eurozone member states.  Only the national obverse sides of the coins differ; the common reverse sides do not.  The coins typically commemorate the anniversaries of historical events or draw attention to current events of special importance.  In 2007, 2009, 2012 and 2015, there were common commemorative coins with only different national inscriptions.  Up to 2015, two hundred and thirty variations of €2 commemorative coins have been minted – six in 2004, eight in 2005, seven in 2006, twenty in 2007 (including thirteen versions of the common issue), ten in 2008, twenty-five in 2009 (including sixteen versions of the common issue), twelve in 2010, sixteen in 2011, thirty in 2012 (including seventeen versions of the common issue), twenty-three in 2013, twenty-six in 2014 and forty-seven in 2015 (including nineteen versions of the common issue).  Finland, Luxembourg, San Marino and the Vatican City are the only countries to have released at least one national commemorative coin every year.  Cyprus has not minted any national commemorative coin yet.

Lincoln cent: The Lincoln cent (or sometimes called Lincoln penny) is a one-cent coin that has been struck by the United States Mint since 1909.  The obverse or heads side was designed by Victor David Brenner, as was the original reverse.  The coin has seen several reverse, or tails, designs and now bears one by Lyndall Bass depicting a Union shield.  All coins struck by the United States government with a value of 1/100 of a dollar are called cents because the United States has always minted coins using decimals.  The penny nickname is a carryover from the coins struck in England, which went to decimals for coins in 1971.

20 yen coin: The 20 yen coin (二十圓硬貨 ) was a denomination of Japanese yen.  These coins were minted in gold, and during their lifespan were the highest denomination of coin that circulated in the country.  The first coins were minted in 1870 following the introduction of a decimal currency system.  Twenty Yen coins spanned three different Imperial eras before mintage was halted in 1932.  Many of these coins were then melted or destroyed as a result of the wars between 1931 and 1945.  These coins are now collected by numismatists for academic study, and by those with a hobby.

Thrymsa: The thrymsa (Old English: "þrymsa" ) was a gold coin minted in seventh-century Anglo-Saxon England.  It originated as a copy of Merovingian tremisses and earlier Roman coins with a high gold content.  Continued debasement between the 630s and the 650s reduced the gold content in newly minted coins such that after c. 655 the percentage of gold in a new coin was less than 35%.  The thrymsa ceased to be minted after about 675 and was superseded by the silver sceat.

Nevada State Museum, Carson City: The Nevada State Museum in Carson City is one of seven Nevada State Museums operated by the Nevada Department of Tourism and Cultural Affairs.  The primary building of the Museum is the former Carson City Mint.  The exhibits include

Carson City Mint: The Carson City Mint was a branch of the United States Mint in Carson City, Nevada.  It primarily minted silver coins; however, it also minted gold coins, with a total face value in dollars nearly equal to that of its silver coins.  The mint minted coins in 21 different years.

Supporting paragraphs: Nevada State Museum, Carson City Carson City Mint
Answer: Carson City Mint