| Value | Category | Cases | |
|---|---|---|---|
| 1 | from last 3 months | 52 | 
                                    
                                    10.8%
                                 | 
| 2 | 4-6 months | 76 | 
                                    
                                    15.8%
                                 | 
| 3 | 7-12 months | 81 | 
                                    
                                    16.8%
                                 | 
| 4 | more than a year | 174 | 
                                    
                                    36.2%
                                 | 
| 7 | don't know | 98 | 
                                    
                                    20.4%
                                 | 
| 8 | refuse to answer | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 1674 |