| Value | Category | Cases | |
|---|---|---|---|
| 1994 | 7 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 1995 | 33 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 1996 | 189 | 
                                                                 
                                    
                                    11.3%
                                 
                                                             | 
                                                        
                    |
| 1997 | 331 | 
                                                                 
                                    
                                    19.9%
                                 
                                                             | 
                                                        
                    |
| 1998 | 420 | 
                                                                 
                                    
                                    25.2%
                                 
                                                             | 
                                                        
                    |
| 1999 | 510 | 
                                                                 
                                    
                                    30.6%
                                 
                                                             | 
                                                        
                    |
| 2000 | 177 | 
                                                                 
                                    
                                    10.6%
                                 
                                                             | 
                                                        
                    |
| 9997 | inconsistent | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 9998 | dk | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 14318 |