Cowell test type
1950-1970
1950-1970
1920
1980
1969
1963
1972
1969
1967
1940
1978
1940
1956
1986
1965
1939
1957
1960
1958
1928
1930
1961
1933-06
1959
1956
1922
1943
1945
1930
1935
1956
1956
1935
1939/10
1960
1945
1956
1956
1923
1957
1939
1929
1956
1962
1958
1933
1925