| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 2 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    |
| 1983 | 7 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 1984 | 11 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 1985 | 26 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1986 | 43 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 1987 | 47 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 1988 | 88 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 1989 | 112 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    |
| 1990 | 137 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 1991 | 167 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 1992 | 199 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    |
| 1993 | 221 | 
                                                                 
                                    
                                    1.6%
                                 
                                                             | 
                                                        
                    |
| 1994 | 206 | 
                                                                 
                                    
                                    1.5%
                                 
                                                             | 
                                                        
                    |
| 1995 | 243 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 1996 | 279 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 1997 | 339 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 1998 | 377 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 1999 | 395 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2000 | 380 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 2001 | 388 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2002 | 460 | 
                                                                 
                                    
                                    3.3%
                                 
                                                             | 
                                                        
                    |
| 2003 | 445 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    |
| 2004 | 422 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    |
| 2005 | 491 | 
                                                                 
                                    
                                    3.5%
                                 
                                                             | 
                                                        
                    |
| 2006 | 496 | 
                                                                 
                                    
                                    3.6%
                                 
                                                             | 
                                                        
                    |
| 2007 | 552 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    |
| 2008 | 616 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    |
| 2009 | 557 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    |
| 2010 | 604 | 
                                                                 
                                    
                                    4.3%
                                 
                                                             | 
                                                        
                    |
| 2011 | 611 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    |
| 2012 | 706 | 
                                                                 
                                    
                                    5.1%
                                 
                                                             | 
                                                        
                    |
| 2013 | 755 | 
                                                                 
                                    
                                    5.4%
                                 
                                                             | 
                                                        
                    |
| 2014 | 827 | 
                                                                 
                                    
                                    6%
                                 
                                                             | 
                                                        
                    |
| 2015 | 867 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    |
| 2016 | 754 | 
                                                                 
                                    
                                    5.4%
                                 
                                                             | 
                                                        
                    |
| 2017 | 736 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2018 | 279 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 9999 | No response | 45 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             |