| Value | Category | Cases | |
|---|---|---|---|
| 1976 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1980 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1990 | 3 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 1995 | 2 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 1997 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1998 | 3 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    |
| 1999 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 2000 | 14 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2002 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 2003 | 4 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    |
| 2004 | 2 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 2005 | 9 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 2006 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 2007 | 4 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    |
| 2008 | 12 | 
                                                                 
                                    
                                    2.4%
                                 
                                                             | 
                                                        
                    |
| 2009 | 8 | 
                                                                 
                                    
                                    1.6%
                                 
                                                             | 
                                                        
                    |
| 2010 | 32 | 
                                                                 
                                    
                                    6.3%
                                 
                                                             | 
                                                        
                    |
| 2011 | 10 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 2012 | 14 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2013 | 15 | 
                                                                 
                                    
                                    2.9%
                                 
                                                             | 
                                                        
                    |
| 2014 | 46 | 
                                                                 
                                    
                                    9%
                                 
                                                             | 
                                                        
                    |
| 2015 | 72 | 
                                                                 
                                    
                                    14.1%
                                 
                                                             | 
                                                        
                    |
| 2016 | 153 | 
                                                                 
                                    
                                    30.1%
                                 
                                                             | 
                                                        
                    |
| 2017 | 48 | 
                                                                 
                                    
                                    9.4%
                                 
                                                             | 
                                                        
                    |
| 2018 | 52 | 
                                                                 
                                    
                                    10.2%
                                 
                                                             |