1973 – 1975
1975 - 1981
1981 - 1983
1983 - 1985
1985 - 1987
1987 - 1989
1989 - 1991
1991 - 1993
1993 - 1995
1995 - 1997
1997 - 1999
1999 - 2003
2003 - 2007
2007 - 2011
2011 - 2015
2015 - 2019