Era
20th century
42
19th century
14
1900-1999
10
1904-1971
9
1905-1936
9
1875-
7
1899-1947
7
1930-1965
7
1809-1865
6
1903
5
1842-1900
4
1857-1938
4
1886-1939
4
1894-1964
4
Revolution, 1917-1921
4
Since 1875
4
1877-1964
3
1895-1956
3
1903-1934
3
1903-1960
3
1904-1934
3
1905 or 6-1936
3
1905-1981
3
1907
3
1910-1976
3
1915-1983
3
1915-1992
3
1917-1969
3
1919-1933
3
1938-2012
3
To 1875
3
1775-1783
2
1800-1899
2
1868-1924
2
1878-1972
2
1883
2
1899
2
1904 or 5-1971
2
1909-1924
2
1911-2001
2
1917-1921
2
1919-2008
2
1920-1992
2
1929
2
1936-2001
2
1939-1945
2
1942-2008
2
1948-1969
2
1961-1975
2
21st century
2
more ...