| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 30 | 
                                                                 
                                    
                                    13.1%
                                 
                                                             | 
                                                        
                    
| 1 | One month or less | 4 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    
| 2 | 8 | 
                                                                 
                                    
                                    3.5%
                                 
                                                             | 
                                                        
                    |
| 3 | 40 | 
                                                                 
                                    
                                    17.5%
                                 
                                                             | 
                                                        
                    |
| 4 | 35 | 
                                                                 
                                    
                                    15.3%
                                 
                                                             | 
                                                        
                    |
| 5 | 29 | 
                                                                 
                                    
                                    12.7%
                                 
                                                             | 
                                                        
                    |
| 6 | 43 | 
                                                                 
                                    
                                    18.8%
                                 
                                                             | 
                                                        
                    |
| 7 | 5 | 
                                                                 
                                    
                                    2.2%
                                 
                                                             | 
                                                        
                    |
| 8 | 10 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    |
| 9 | 3 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    |
| 10 | 8 | 
                                                                 
                                    
                                    3.5%
                                 
                                                             | 
                                                        
                    |
| 11 | 4 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 12 | 10 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 987 |