| 年度 | 数值 | 单位 | 发布日期 |
|---|
| 1998/1999 | 24 | 千公顷 | 2026-9 |
| 1997/1998 | 13 | 千公顷 | 2026-9 |
| 1996/1997 | 12 | 千公顷 | 2026-9 |
| 1995/1996 | 10 | 千公顷 | 2026-9 |
| 1994/1995 | 12 | 千公顷 | 2026-9 |
| 1993/1994 | 16 | 千公顷 | 2026-9 |
| 1992/1993 | 28 | 千公顷 | 2026-9 |
| 1991/1992 | 25 | 千公顷 | 2026-9 |
| 1990/1991 | 33 | 千公顷 | 2026-9 |
| 1989/1990 | 54 | 千公顷 | 2026-9 |
| 1988/1989 | 66 | 千公顷 | 2026-9 |
| 1987/1988 | 36 | 千公顷 | 2026-9 |
| 1986/1987 | 23 | 千公顷 | 2026-9 |
| 1985/1986 | 24 | 千公顷 | 2026-9 |
| 1984/1985 | 30 | 千公顷 | 2026-9 |
| 1983/1984 | 30 | 千公顷 | 2026-9 |
| 1982/1983 | 24 | 千公顷 | 2026-9 |
| 1981/1982 | 24 | 千公顷 | 2026-9 |
| 1980/1981 | 20 | 千公顷 | 2026-9 |
| 1979/1980 | 20 | 千公顷 | 2026-9 |
| 1978/1979 | 19 | 千公顷 | 2026-9 |
| 1977/1978 | 29 | 千公顷 | 2026-9 |
| 1976/1977 | 39 | 千公顷 | 2026-9 |
| 1975/1976 | 25 | 千公顷 | 2026-9 |
| 1974/1975 | 15 | 千公顷 | 2026-9 |
| 1973/1974 | 0 | 千公顷 | 2026-9 |
| 1970/1971 | 0 | 千公顷 | 2026-9 |
| 1969/1970 | 0 | 千公顷 | 2026-9 |
| 1968/1969 | 0 | 千公顷 | 2026-9 |
| 1967/1968 | 0 | 千公顷 | 2026-9 |
| 1966/1967 | 0 | 千公顷 | 2026-9 |
| 1965/1966 | 0 | 千公顷 | 2026-9 |
| 1964/1965 | 0 | 千公顷 | 2026-9 |