| Value | Category | Cases | |
|---|---|---|---|
| 1996 | 2 | 
                                    
                                    1.1%
                                 | |
| 1998 | 5 | 
                                    
                                    2.8%
                                 | |
| 1999 | 6 | 
                                    
                                    3.4%
                                 | |
| 2000 | 12 | 
                                    
                                    6.7%
                                 | |
| 2001 | 1 | 
                                    
                                    0.6%
                                 | |
| 2002 | 3 | 
                                    
                                    1.7%
                                 | |
| 2003 | 7 | 
                                    
                                    3.9%
                                 | |
| 2004 | 13 | 
                                    
                                    7.3%
                                 | |
| 2005 | 9 | 
                                    
                                    5.1%
                                 | |
| 2006 | 14 | 
                                    
                                    7.9%
                                 | |
| 2007 | 6 | 
                                    
                                    3.4%
                                 | |
| 2008 | 6 | 
                                    
                                    3.4%
                                 | |
| 2009 | 8 | 
                                    
                                    4.5%
                                 | |
| 2010 | 3 | 
                                    
                                    1.7%
                                 | |
| 2011 | 6 | 
                                    
                                    3.4%
                                 | |
| 2013 | 7 | 
                                    
                                    3.9%
                                 | |
| 2014 | 9 | 
                                    
                                    5.1%
                                 | |
| 2015 | 1 | 
                                    
                                    0.6%
                                 | |
| Missing value | 60 | 
                                    
                                    33.7%
                                 |