15 August 1947 – 31 January 1961

(13 years, 169 days)

1 February 1961 – 18 February 1961

(17 days)

18 February 1961 – 2 October 1963

(2 years, 226 days)

2 October 1963 – 5 March 1967

(3 years, 154 days)

5 March 1967 – 28 January 1968

(329 days)

28 January 1968 – 1 February 1968

(4 days)

1 February 1968 – 22 March 1968

(50 days)

22 March 1968 – 29 June 1968 (99 days)

22 June 1969 – 4 July 1969 (12 days)

2 June 1971 – 9 January 1972 (221 days)

26 February 1969 – 22 June 1969

(116 days)

16 February 1970 – 22 December 1970

(309 days)

22 December 1970 – 2 June 1971 (162 days)

24 June 1977 – 21 April 1979 (1 year, 301 days)

19 March 1972 – 2 July 1973 (1 year, 105 days)

2 July 1973 – 11 April 1975 (1 year, 283 days)

11 April 1975 – 30 April 1977 (2 years, 19 days)

8 June 1980 – 14 August 1983 (3 years, 67 days)

6 December 1989 – 10 March 1990 (94 days)

21 April 1979 – 17 February 1980 (302 days)

14 August 1983 – 12 March 1985 (1 year, 210 days)

12 March 1985 – 13 February 1988 (2 years, 338 days)

13 February 1988 – 10 March 1989 (1 year, 25 days)

11 March 1989 – 6 December 1989 (270 days)

10 March 1990 – 28 March 1995 (5 years, 18 days)

4 April 1995 – 25 July 1997 (2 years, 112 days)

25 July 1997 – 11 February 1999 (1 year, 201 days)

9 March 1999 – 2 March 2000 (359 days)

11 March 2000 – 6 March 2005 (4 years, 360 days)

3 March 2000 – 10 March 2000 (7 days)

24 November 2005 – 20 May 2014 (8 years, 177 days)

22 February 2015 – Incumbent (10 years, 265 days)

20 May 2014 – 22 February 201 (278 days)