| Value | Category | Cases | |
|---|---|---|---|
| 1 | 6 years old or younger | 36765 | 
                                    
                                    12.4%
                                 | 
| 2 | 7-9 years old | 113587 | 
                                    
                                    38.3%
                                 | 
| 3 | 10-12 years old | 105825 | 
                                    
                                    35.7%
                                 | 
| 4 | 13 years old or older | 38130 | 
                                    
                                    12.9%
                                 | 
| 5 | Never | 1998 | 
                                    
                                    0.7%
                                 | 
| 7 | N/A | 173656 | |
| 8 | Invalid | 586 | |
| 9 | Missing | 14943 |