| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 | 
                                                                 
                                    
                                    5.1%
                                 
                                                             | 
                                                        
                    
| 1 | One month or less | 29 | 
                                                                 
                                    
                                    12.4%
                                 
                                                             | 
                                                        
                    
| 2 | 4 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 3 | 31 | 
                                                                 
                                    
                                    13.2%
                                 
                                                             | 
                                                        
                    |
| 4 | 4 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 5 | 1 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 6 | 34 | 
                                                                 
                                    
                                    14.5%
                                 
                                                             | 
                                                        
                    |
| 7 | 3 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    |
| 8 | 8 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 9 | 3 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    |
| 10 | 16 | 
                                                                 
                                    
                                    6.8%
                                 
                                                             | 
                                                        
                    |
| 11 | 5 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    |
| 12 | 84 | 
                                                                 
                                    
                                    35.9%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 1284 |