| Value | Category | Cases | |
|---|---|---|---|
| 1987 | 1 | 
                                    
                                    0%
                                 | |
| 1988 | 1 | 
                                    
                                    0%
                                 | |
| 1989 | 2 | 
                                    
                                    0.1%
                                 | |
| 1990 | 11 | 
                                    
                                    0.3%
                                 | |
| 1991 | 24 | 
                                    
                                    0.7%
                                 | |
| 1992 | 25 | 
                                    
                                    0.7%
                                 | |
| 1993 | 14 | 
                                    
                                    0.4%
                                 | |
| 1994 | 42 | 
                                    
                                    1.2%
                                 | |
| 1995 | 31 | 
                                    
                                    0.9%
                                 | |
| 1996 | 50 | 
                                    
                                    1.5%
                                 | |
| 1997 | 63 | 
                                    
                                    1.9%
                                 | |
| 1998 | 84 | 
                                    
                                    2.5%
                                 | |
| 1999 | 53 | 
                                    
                                    1.6%
                                 | |
| 2000 | 94 | 
                                    
                                    2.8%
                                 | |
| 2001 | 60 | 
                                    
                                    1.8%
                                 | |
| 2002 | 86 | 
                                    
                                    2.5%
                                 | |
| 2003 | 118 | 
                                    
                                    3.5%
                                 | |
| 2004 | 77 | 
                                    
                                    2.3%
                                 | |
| 2005 | 58 | 
                                    
                                    1.7%
                                 | |
| 2006 | 92 | 
                                    
                                    2.7%
                                 | |
| 2007 | 84 | 
                                    
                                    2.5%
                                 | |
| 2008 | 68 | 
                                    
                                    2%
                                 | |
| 2009 | 85 | 
                                    
                                    2.5%
                                 | |
| 2010 | 117 | 
                                    
                                    3.5%
                                 | |
| 2011 | 117 | 
                                    
                                    3.5%
                                 | |
| 2012 | 122 | 
                                    
                                    3.6%
                                 | |
| 2013 | 163 | 
                                    
                                    4.8%
                                 | |
| 2014 | 261 | 
                                    
                                    7.7%
                                 | |
| 2015 | 281 | 
                                    
                                    8.3%
                                 | |
| 2016 | 332 | 
                                    
                                    9.8%
                                 | |
| 2017 | 382 | 
                                    
                                    11.3%
                                 | |
| 2018 | 358 | 
                                    
                                    10.6%
                                 | |
| 2019 | 10 | 
                                    
                                    0.3%
                                 | |
| 9999 | NO RESPONSE | 7 | 
                                    
                                    0.2%
                                 | 
| Sysmiss | 18 | 
                                    
                                    0.5%
                                 |