| Value | Category | Cases | |
|---|---|---|---|
| 1968 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1978 | 3 | 
                                                                 
                                    
                                    8.3%
                                 
                                                             | 
                                                        
                    |
| 1979 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1983 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1988 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1990 | 2 | 
                                                                 
                                    
                                    5.6%
                                 
                                                             | 
                                                        
                    |
| 1991 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1992 | 4 | 
                                                                 
                                    
                                    11.1%
                                 
                                                             | 
                                                        
                    |
| 1993 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1994 | 2 | 
                                                                 
                                    
                                    5.6%
                                 
                                                             | 
                                                        
                    |
| 1995 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1999 | 2 | 
                                                                 
                                    
                                    5.6%
                                 
                                                             | 
                                                        
                    |
| 2002 | 3 | 
                                                                 
                                    
                                    8.3%
                                 
                                                             | 
                                                        
                    |
| 2003 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2007 | 1 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2010 | 4 | 
                                                                 
                                    
                                    11.1%
                                 
                                                             | 
                                                        
                    |
| 2011 | 3 | 
                                                                 
                                    
                                    8.3%
                                 
                                                             | 
                                                        
                    |
| 2015 | 4 | 
                                                                 
                                    
                                    11.1%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 24559 |