The history of the Republic of Singapore began when Singapore was expelled from Malaysia and became an independent republic on 9 August 1965. After the separation, the fledgling nation had to become self-sufficient, and faced problems including mass unemployment, housing shortages and lack of land and natural resources such as petroleum.During Lee Kuan Yew's term as prime minister from 1959 to 1990, his administration curbed unemployment, raised the standard of living and implemented a large-scale public housing programme. The country's economic infrastructure was developed, racial tension was eliminated and an independent national defence system was created. Singapore evolved from a to developed country status towards the end of the 20th century.