| Value | Category | Cases | |
|---|---|---|---|
| 1977 | 1 | 
                                    
                                    0.5%
                                 | |
| 1985 | 1 | 
                                    
                                    0.5%
                                 | |
| 1986 | 1 | 
                                    
                                    0.5%
                                 | |
| 1990 | 2 | 
                                    
                                    1%
                                 | |
| 1994 | 1 | 
                                    
                                    0.5%
                                 | |
| 1995 | 1 | 
                                    
                                    0.5%
                                 | |
| 1997 | 1 | 
                                    
                                    0.5%
                                 | |
| 1998 | 3 | 
                                    
                                    1.5%
                                 | |
| 2000 | 2 | 
                                    
                                    1%
                                 | |
| 2001 | 4 | 
                                    
                                    2.1%
                                 | |
| 2002 | 2 | 
                                    
                                    1%
                                 | |
| 2005 | 4 | 
                                    
                                    2.1%
                                 | |
| 2006 | 2 | 
                                    
                                    1%
                                 | |
| 2007 | 1 | 
                                    
                                    0.5%
                                 | |
| 2008 | 4 | 
                                    
                                    2.1%
                                 | |
| 2009 | 3 | 
                                    
                                    1.5%
                                 | |
| 2010 | 5 | 
                                    
                                    2.6%
                                 | |
| 2011 | 6 | 
                                    
                                    3.1%
                                 | |
| 2012 | 8 | 
                                    
                                    4.1%
                                 | |
| 2013 | 6 | 
                                    
                                    3.1%
                                 | |
| 2014 | 5 | 
                                    
                                    2.6%
                                 | |
| 2015 | 9 | 
                                    
                                    4.6%
                                 | |
| 2016 | 14 | 
                                    
                                    7.2%
                                 | |
| 2017 | 16 | 
                                    
                                    8.2%
                                 | |
| 2018 | 19 | 
                                    
                                    9.7%
                                 | |
| 2019 | 30 | 
                                    
                                    15.4%
                                 | |
| 2020 | 31 | 
                                    
                                    15.9%
                                 | |
| 2021 | 13 | 
                                    
                                    6.7%
                                 | |
| Sysmiss | 1305 |