| Value | Category | Cases | |
|---|---|---|---|
| 1 | Before 1960 | 8 | 
                                                                 
                                    
                                    2.9%
                                 
                                                             | 
                                                        
                    
| 2 | 1960-1969 | 9 | 
                                                                 
                                    
                                    3.3%
                                 
                                                             | 
                                                        
                    
| 3 | 1970-1979 | 18 | 
                                                                 
                                    
                                    6.6%
                                 
                                                             | 
                                                        
                    
| 4 | 1980-1989 | 49 | 
                                                                 
                                    
                                    18%
                                 
                                                             | 
                                                        
                    
| 5 | 1990-1999 | 43 | 
                                                                 
                                    
                                    15.8%
                                 
                                                             | 
                                                        
                    
| 6 | 2000 and after | 145 | 
                                                                 
                                    
                                    53.3%
                                 
                                                             |