Under the constitution of 1853, the President served for six years, with no possibility of consecutive reelection. In 1949, the constitution was amended to allow the president to run for an unlimited number of six-year terms. This provision was repealed in 1957. After the 1966 military coup, the rulers shortened the presidential term to four years, but there was a period of political instability during these terms, which had led to the situation that they were never completed. With the restoration of democracy in 1983, the term was restored to six years.