| 年度 | 数值 | 单位 | 发布日期 |
|---|
| 1992/1993 | 2.3 | 吨/公顷 | 2026-9 |
| 1991/1992 | 2.321 | 吨/公顷 | 2026-9 |
| 1990/1991 | 2.324 | 吨/公顷 | 2026-9 |
| 1989/1990 | 2.258 | 吨/公顷 | 2026-9 |
| 1988/1989 | 2.067 | 吨/公顷 | 2026-9 |
| 1987/1988 | 2.296 | 吨/公顷 | 2026-9 |
| 1986/1987 | 2.296 | 吨/公顷 | 2026-9 |
| 1985/1986 | 1.826 | 吨/公顷 | 2026-9 |
| 1984/1985 | 1.593 | 吨/公顷 | 2026-9 |
| 1983/1984 | 1.864 | 吨/公顷 | 2026-9 |
| 1982/1983 | 1.636 | 吨/公顷 | 2026-9 |
| 1981/1982 | 1.737 | 吨/公顷 | 2026-9 |
| 1980/1981 | 1.25 | 吨/公顷 | 2026-9 |
| 1979/1980 | 1.238 | 吨/公顷 | 2026-9 |
| 1978/1979 | 1.364 | 吨/公顷 | 2026-9 |
| 1977/1978 | 1.222 | 吨/公顷 | 2026-9 |
| 1976/1977 | 1.167 | 吨/公顷 | 2026-9 |
| 1975/1976 | 1 | 吨/公顷 | 2026-9 |
| 1974/1975 | 1 | 吨/公顷 | 2026-9 |
| 1973/1974 | 1.75 | 吨/公顷 | 2026-9 |
| 1972/1973 | 1.5 | 吨/公顷 | 2026-9 |