| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not given | 412 | 
                                                                 
                                    
                                    29.3%
                                 
                                                             | 
                                                        
                    
| 2011 | 4 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 2012 | 270 | 
                                                                 
                                    
                                    19.2%
                                 
                                                             | 
                                                        
                    |
| 2013 | 404 | 
                                                                 
                                    
                                    28.7%
                                 
                                                             | 
                                                        
                    |
| 2014 | 312 | 
                                                                 
                                    
                                    22.2%
                                 
                                                             | 
                                                        
                    |
| 4444 | Marked on card | 2 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    
| 9997 | Inconsistent | 2 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    
| 9998 | DK | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 9999 | Missing | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1322 |