years of the Improved Flora and Fauna Series which featured reduced sizes for all denominations. The Flora and Fauna Series was struck from 1983 through 1994. Philippine issues since 1995 In 1995, the new BSP Series was introduced, which is still circulating today. Only this current series of coins are legal tender after January 2, 1998, when the Bangko Sentral ng Pilipinas issued BSP Circular No. 81 which called for the demonetization of all previous existing Central Bank coins minted before 1995. Coins under this series originally included 1, 5, 10 and 25-sentimo, 1-piso and 5-piso. A bimetallic 10-piso coin was added in 2000 to replace the 10-piso note. Recently, fake 10 and 5-piso coins dating 2001 and 2002 have entered circulation. Because of this, the Bangko Sentral ng Pilipinas issued a warning and several security measures on importing and falsifying Philippine coins. And it is because the BSP has announced that there is an artificial shortage of coins last June 2006. The BSP has asked the public to use all small coins or to have them exchanged for banknotes in local banks or other financial institution. Denominations worth 25 sentimo (~US$0.005) and below are still issued but have been increasingly regarded as a nuisance. Proposals to retire and demonetize all coins less than one peso in value have been rejected by the government and the BSP. On November 29, 2017, the Bangko Sentral ng Pilipinas announced the release of the first coin in the New Generation Currency Series for circulation starting December 2017. As a tribute to the 154th birth anniversary of Andres Bonifacio, the first coin to be released was the new silver-colored 5-peso coin featuring Bonifacio on the obverse, replacing Emilio Aguinaldo. The reverse features the Tayabak plant and the new BSP logo. The rest of the NGC coin series were presented on March 26, 2018. The rest of the series was released March 2018 consisting of 1, 5 and 25-sentimo and 1, 5 and 10-piso. A 20-peso coin was added to the series on December 17, 2019, in order to replace the overused 20-piso banknote with a coin that could last 10–15 years longer in circulation. Formerly circulating coins Spanish administration The Philippines under U.S. Sovereignty Commonwealth Issues In 1935, when the Commonwealth was established by the Congress of the United States, they issued a three-piece commemorative set (that sold very poorly) to commemorate the occasion.