| Value |
Category |
| 1961 |
|
| 1962 |
|
| 1964 |
|
| 1965 |
|
| 1966 |
|
| 1967 |
|
| 1969 |
|
| 1970 |
|
| 1971 |
|
| 1972 |
|
| 1975 |
|
| 1981 |
|
| 9898 |
don't know |
| Sysmiss |
|
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.
