| Value | Category | Cases | |
|---|---|---|---|
| 1991 | 1 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 1995 | 1 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 1999 | 1 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2004 | 1 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2005 | 2 | 
                                                                 
                                    
                                    6.9%
                                 
                                                             | 
                                                        
                    |
| 2007 | 1 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2008 | 1 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2009 | 1 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2010 | 2 | 
                                                                 
                                    
                                    6.9%
                                 
                                                             | 
                                                        
                    |
| 2011 | 2 | 
                                                                 
                                    
                                    6.9%
                                 
                                                             | 
                                                        
                    |
| 2012 | 2 | 
                                                                 
                                    
                                    6.9%
                                 
                                                             | 
                                                        
                    |
| 2013 | 12 | 
                                                                 
                                    
                                    41.4%
                                 
                                                             | 
                                                        
                    |
| 2014 | 2 | 
                                                                 
                                    
                                    6.9%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | .don't know | 0 | |
| Sysmiss | .qre refused | 0 | |
| Sysmiss | .refusal | 0 | |
| Sysmiss | .skip | 0 | |
| Sysmiss | .x. censored | 0 | |
| Sysmiss | 1405 |