| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 1 | 
                                    
                                    0%
                                 | |
| 1985 | 1 | 
                                    
                                    0%
                                 | |
| 1986 | 10 | 
                                    
                                    0.3%
                                 | |
| 1987 | 11 | 
                                    
                                    0.3%
                                 | |
| 1988 | 30 | 
                                    
                                    0.9%
                                 | |
| 1989 | 39 | 
                                    
                                    1.2%
                                 | |
| 1990 | 45 | 
                                    
                                    1.3%
                                 | |
| 1991 | 38 | 
                                    
                                    1.1%
                                 | |
| 1992 | 53 | 
                                    
                                    1.6%
                                 | |
| 1993 | 91 | 
                                    
                                    2.7%
                                 | |
| 1994 | 75 | 
                                    
                                    2.2%
                                 | |
| 1995 | 84 | 
                                    
                                    2.5%
                                 | |
| 1996 | 84 | 
                                    
                                    2.5%
                                 | |
| 1997 | 100 | 
                                    
                                    2.9%
                                 | |
| 1998 | 106 | 
                                    
                                    3.1%
                                 | |
| 1999 | 89 | 
                                    
                                    2.6%
                                 | |
| 2000 | 115 | 
                                    
                                    3.4%
                                 | |
| 2001 | 119 | 
                                    
                                    3.5%
                                 | |
| 2002 | 113 | 
                                    
                                    3.3%
                                 | |
| 2003 | 98 | 
                                    
                                    2.9%
                                 | |
| 2004 | 87 | 
                                    
                                    2.6%
                                 | |
| 2005 | 63 | 
                                    
                                    1.9%
                                 | |
| 2006 | 95 | 
                                    
                                    2.8%
                                 | |
| 2007 | 103 | 
                                    
                                    3%
                                 | |
| 2008 | 131 | 
                                    
                                    3.9%
                                 | |
| 2009 | 124 | 
                                    
                                    3.7%
                                 | |
| 2010 | 143 | 
                                    
                                    4.2%
                                 | |
| 2011 | 142 | 
                                    
                                    4.2%
                                 | |
| 2012 | 159 | 
                                    
                                    4.7%
                                 | |
| 2013 | 135 | 
                                    
                                    4%
                                 | |
| 2014 | 203 | 
                                    
                                    6%
                                 | |
| 2015 | 161 | 
                                    
                                    4.7%
                                 | |
| 2016 | 180 | 
                                    
                                    5.3%
                                 | |
| 2017 | 169 | 
                                    
                                    5%
                                 | |
| 2018 | 168 | 
                                    
                                    5%
                                 | |
| 2019 | 1 | 
                                    
                                    0%
                                 | |
| 9999 | NO RESPONSE | 7 | 
                                    
                                    0.2%
                                 | 
| Sysmiss | 18 | 
                                    
                                    0.5%
                                 |