The kwacha (ISO 4217: MWK) is the currency of Malawi as of 1971, replacing the Malawian pound. It is divided into 100 tambala. The kwacha replaced other types of currency, namely the UK pound sterling, the South African rand and the Rhodesian dollar, that had previously circulated through the Malawian economy. The exchange rate of the kwacha undergoes fixed periodical adjustments, but since 1994 the exchange rate has floated. In 2005, administrative measures were put in place by Bingu wa Mutharika to peg the exchange rate with other currencies. Banknotes are issued by the Reserve Bank of Malawi. In May 2012, the Reserve Bank of Malawi devalued the kwacha by 34% and unpegged it from the United States dollar.