| Mill operation | Eastern | Central | Western | Total |
| Less than 4 months | 1 | 0 | 3 | 4 |
| 4 - 6 months | 2 | 6 | 5 | 13 |
| 7 - 9 months | 9 | 5 | 7 | 21 |
| More than 9 months | 3 | 5 | 4 | 12 |
| Total | 15 | 16 | 19 | 50 |