| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 213 | 
                                    
                                    10.8%
                                 | |
| 1997 | 298 | 
                                    
                                    15.1%
                                 | |
| 1998 | 380 | 
                                    
                                    19.3%
                                 | |
| 1999 | 534 | 
                                    
                                    27.1%
                                 | |
| 2000 | 542 | 
                                    
                                    27.5%
                                 | |
| 9997 | inconsistent | 2 | 
                                    
                                    0.1%
                                 | 
| 9998 | dk | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 12977 |