Era
1971-1975
9
1986-1991
8
1981-1985
7
1945-
6
1975-1985
6
1917-1928
5
20th century
5
1976-
4
Since 1945
4
1957-
3
1985-1991
3
1900 - 1999
2
1900-1999
2
1945-1991
2
1966-
2
1976-1980
2
Since 1976
2
1917 - 1928
1
1917-
1
1917-1936
1
1917-1945
1
1918 - 1945
1
1918-
1
1918-1945
1
1945-1971
1
1947-
1
1959 - 1965
1
1959-1965
1
1960-
1
1965-1975
1
1965-1985
1
1966 - 1970
1
1966-1970
1
1971-
1
1971-1990
1
1975-1991
1
1976-1985
1
1981 - 1985
1
1981-
1
1985 - 1991
1
1986 - 1991
1
Since 1917
1
Since 1918
1
Since 1947
1
Since 1960
1
Since 1966
1