| Value | Category | Cases | |
|---|---|---|---|
| 1 | No, never | 401264 | 
                                    
                                    91.9%
                                 | 
| 2 | Yes, once | 30709 | 
                                    
                                    7%
                                 | 
| 3 | Yes, twice or more | 4717 | 
                                    
                                    1.1%
                                 | 
| 7 | N/A | 25551 | |
| 8 | Invalid | 556 | |
| 9 | Missing | 22693 |