| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 22 | 
                                    
                                    1.1%
                                 | |
| 1996 | 267 | 
                                    
                                    12.9%
                                 | |
| 1997 | 276 | 
                                    
                                    13.3%
                                 | |
| 1998 | 363 | 
                                    
                                    17.5%
                                 | |
| 1999 | 558 | 
                                    
                                    26.9%
                                 | |
| 2000 | 586 | 
                                    
                                    28.3%
                                 | |
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 12874 |