| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 4 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1996 | 121 | 
                                                                 
                                    
                                    7%
                                 
                                                             | 
                                                        
                    |
| 1997 | 167 | 
                                                                 
                                    
                                    9.7%
                                 
                                                             | 
                                                        
                    |
| 1998 | 307 | 
                                                                 
                                    
                                    17.9%
                                 
                                                             | 
                                                        
                    |
| 1999 | 555 | 
                                                                 
                                    
                                    32.3%
                                 
                                                             | 
                                                        
                    |
| 2000 | 563 | 
                                                                 
                                    
                                    32.8%
                                 
                                                             | 
                                                        
                    |
| 9997 | inconsistent | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    
| 9998 | dk | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 5037 |