| Value | Category | Cases | |
|---|---|---|---|
| 1 | Before 1960 | 8 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    
| 2 | 1960-1969 | 8 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    
| 3 | 1970-1979 | 15 | 
                                                                 
                                    
                                    5.5%
                                 
                                                             | 
                                                        
                    
| 4 | 1980-1989 | 41 | 
                                                                 
                                    
                                    15.1%
                                 
                                                             | 
                                                        
                    
| 5 | 1990-1999 | 43 | 
                                                                 
                                    
                                    15.9%
                                 
                                                             | 
                                                        
                    
| 6 | 2000-2009 | 102 | 
                                                                 
                                    
                                    37.6%
                                 
                                                             | 
                                                        
                    
| 7 | 2010 and more | 54 | 
                                                                 
                                    
                                    19.9%
                                 
                                                             |