| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 1993 | 3 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 1994 | 2 | 
                                                                 
                                    
                                    0.7%
                                 
                                                             | 
                                                        
                    |
| 1995 | 9 | 
                                                                 
                                    
                                    3.1%
                                 
                                                             | 
                                                        
                    |
| 1996 | 81 | 
                                                                 
                                    
                                    28.3%
                                 
                                                             | 
                                                        
                    |
| 1997 | 76 | 
                                                                 
                                    
                                    26.6%
                                 
                                                             | 
                                                        
                    |
| 1998 | 109 | 
                                                                 
                                    
                                    38.1%
                                 
                                                             | 
                                                        
                    |
| 1999 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 7777 | Don't Know | 4 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    
| 9999 | Refused | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 4985 |