26 January 1950 to 13 May 1962 12 years, 107 days
13 May 1962 to 13 May 1967 5 years
13 May 1967 to 3 May 1969 1 year, 355 days
24 August 1969 to 24 August 1974 5 years
24 August 1974 to 11 February 1977 2 years, 171 days
25 July 1977 to 25 July 1982 5 years
25 July 1982 to 25 July 1987 5 years
25 July 1987 to 25 July 1992 5 years
25 July 1992 to 25 July 1997 5 years
25 July 1997 to 25 July 2002 5 years
25 July 2002 to 25 July 2007 5 years
25 July 2007 to 25 July 2012 5 years
25 July 2012 to 25 July 2017 5 years
25 July 2017 to 25 July 2022 5 years
25 July 2022 to Incumbent 2 years, 45 days