sentences:  1990, but was then elected by direct popular vote in a process of decentralization that saw the prefectures become local government units.Municipal elections in Greece are held every four years and voting for the election of prefects and mayors was carried out concurrently but with separate ballots.The 2010 Kallikratis plan, which took effect on 1 January 2011, abolished the prefectures as separate administrative units, and transformed them into regional units within the country's thirteen administrative regions.