Value |
Category |
-2 |
na |
-1 |
missing |
1988 |
|
1989 |
|
1990 |
|
1991 |
|
1994 |
|
1995 |
|
1996 |
|
1997 |
|
1998 |
|
1999 |
|
2000 |
|
2001 |
|
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.