| Value |
Category |
| 98 |
ns/nr |
| 1977 |
|
| 1978 |
|
| 1979 |
|
| 1980 |
|
| 1981 |
|
| 1982 |
|
| 1983 |
|
| 1984 |
|
| 1985 |
|
| 1986 |
|
| 1987 |
|
| 1988 |
|
| 1989 |
|
| 1990 |
|
| 1991 |
|
| 1992 |
|
| 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.