| Value | Category | Cases | |
|---|---|---|---|
| 1988 | 2 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    |
| 1993 | 2 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    |
| 1994 | 2 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    |
| 1995 | 5 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 1996 | 53 | 
                                                                 
                                    
                                    29%
                                 
                                                             | 
                                                        
                    |
| 1997 | 52 | 
                                                                 
                                    
                                    28.4%
                                 
                                                             | 
                                                        
                    |
| 1998 | 64 | 
                                                                 
                                    
                                    35%
                                 
                                                             | 
                                                        
                    |
| 7777 | Don't Know | 3 | 
                                                                 
                                    
                                    1.6%
                                 
                                                             | 
                                                        
                    
| 9999 | Refused | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 5088 |