| Value |
Category |
| 1928 |
1928 or earlier |
| 1929 |
1929 |
| 1930 |
1930 |
| 1931 |
1931 |
| 1932 |
1932 |
| 1933 |
1933 |
| 1934 |
1934 |
| 1935 |
1935 |
| 1936 |
1936 |
| 1937 |
1937 |
| 1938 |
1938 |
| 1939 |
1939 |
| 1940 |
1940 |
| 1941 |
1941 |
| 1942 |
1942 |
| 1943 |
1943 |
| 1944 |
1944 |
| 1945 |
1945 |
| 1946 |
1946 |
| 1947 |
1947 |
| 1948 |
1948 |
| 1949 |
1949 |
| 1950 |
1950 |
| 1951 |
1951 |
| 1952 |
1952 |
| 1953 |
1953 |
| 1954 |
1954 |
| 1955 |
1955 |
| 1956 |
1956 |
| 1957 |
1957 |
| 1958 |
1958 |
| 1959 |
1959 |
| 1960 |
1960 |
| 1961 |
1961 |
| 1962 |
1962 |
| 1963 |
1963 |
| 1964 |
1964 |
| 1965 |
1965 |
| 1966 |
1966 |
| 1967 |
1967 |
| 1968 |
1968 |
| 1969 |
1969 |
| 1970 |
1970 |
| 1971 |
1971 |
| 1972 |
1972 |
| 1973 |
1973 |
| 1974 |
1974 |
| 1975 |
1975 or later |
| 9998 |
Unknown |
| 9999 |
NIU (not in universe) |
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.