| spare time spent on study | subtotal (person) | percentage (%) |
| less than 5 hours | 115 | 2 6 |
| 5 and 10 hours | 171 | 3 8 |
| between 10 and 20 hours | 9 6 | 2 2 |
| more than 20 hours | 6 1 | 1 4 |
| total | 443 | 100 |