| Value | Category | Cases | |
|---|---|---|---|
| 2010 | 6 | 
                                                                 
                                    
                                    9%
                                 
                                                             | 
                                                        
                    |
| 2011 | 8 | 
                                                                 
                                    
                                    11.9%
                                 
                                                             | 
                                                        
                    |
| 2012 | 10 | 
                                                                 
                                    
                                    14.9%
                                 
                                                             | 
                                                        
                    |
| 2013 | 13 | 
                                                                 
                                    
                                    19.4%
                                 
                                                             | 
                                                        
                    |
| 2014 | 18 | 
                                                                 
                                    
                                    26.9%
                                 
                                                             | 
                                                        
                    |
| 2015 | 11 | 
                                                                 
                                    
                                    16.4%
                                 
                                                             | 
                                                        
                    |
| 2016 | 1 | 
                                                                 
                                    
                                    1.5%
                                 
                                                             |