| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 22 | 
                                    
                                    1.1%
                                 | |
| 1996 | 259 | 
                                    
                                    12.4%
                                 | |
| 1997 | 281 | 
                                    
                                    13.5%
                                 | |
| 1998 | 364 | 
                                    
                                    17.5%
                                 | |
| 1999 | 564 | 
                                    
                                    27.1%
                                 | |
| 2000 | 591 | 
                                    
                                    28.4%
                                 | |
| 9997 | inconsistent | 0 | 
                                    
                                    0%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 12865 |