| 年度 | 数值 | 单位 | 发布日期 |
|---|---|---|---|
| 1990/1991 | 2 | 吨/公顷 | 2026-9 |
| 1989/1990 | 2.25 | 吨/公顷 | 2026-9 |
| 1988/1989 | 2.25 | 吨/公顷 | 2026-9 |
| 1987/1988 | 2.25 | 吨/公顷 | 2026-9 |
| 1986/1987 | 2.286 | 吨/公顷 | 2026-9 |
| 1985/1986 | 1.5 | 吨/公顷 | 2026-9 |
| 1984/1985 | 2.25 | 吨/公顷 | 2026-9 |
| 1983/1984 | 2.25 | 吨/公顷 | 2026-9 |
| 1982/1983 | 1.667 | 吨/公顷 | 2026-9 |
| 1981/1982 | 1 | 吨/公顷 | 2026-9 |
| 1980/1981 | 1 | 吨/公顷 | 2026-9 |
| 1979/1980 | 0 | 吨/公顷 | 2026-9 |
| 1978/1979 | 1 | 吨/公顷 | 2026-9 |