| Value | Category | Cases | |
|---|---|---|---|
| 1958 | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 2002 | 5 | 
                                                                 
                                    
                                    0.7%
                                 
                                                             | 
                                                        
                    |
| 2006 | 4 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 2007 | 7 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 2009 | 8 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    |
| 2010 | 28 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    |
| 2011 | 15 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    |
| 2012 | 25 | 
                                                                 
                                    
                                    3.6%
                                 
                                                             | 
                                                        
                    |
| 2013 | 283 | 
                                                                 
                                    
                                    40.3%
                                 
                                                             | 
                                                        
                    |
| 2014 | 136 | 
                                                                 
                                    
                                    19.4%
                                 
                                                             | 
                                                        
                    |
| 9998 | dont know | 40 | 
                                                                 
                                    
                                    5.7%
                                 
                                                             | 
                                                        
                    
| 9999 | no visit since the departure | 150 | 
                                                                 
                                    
                                    21.4%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 15728 |