| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1990-1959 | 31 | 
                                                                 
                                    
                                    13.7%
                                 
                                                             | 
                                                        
                    
| 2 | 1960-1979 | 47 | 
                                                                 
                                    
                                    20.7%
                                 
                                                             | 
                                                        
                    
| 3 | 1980-1989 | 71 | 
                                                                 
                                    
                                    31.3%
                                 
                                                             | 
                                                        
                    
| 4 | After 1990 | 78 | 
                                                                 
                                    
                                    34.4%
                                 
                                                             |