| Value | Category | Cases | |
|---|---|---|---|
| 1 | ONLY THIS YEAR'S PRODUCTION | 459 |
56.5%
|
| 2 | ONLY PREVIOUS YEAR'S PRODUCTION | 101 |
12.4%
|
| 3 | MAINLY THIS YEAR'S PRODUCTION | 115 |
14.2%
|
| 4 | MAINLY LAST YEAR'S PRODUCTION | 137 |
16.9%
|