| 年度 | 数值 | 单位 | 发布日期 |
| 1998/1999 | 1.183 | 吨/公顷 | 2026-9 |
| 1997/1998 | 1.103 | 吨/公顷 | 2026-9 |
| 1996/1997 | 1.297 | 吨/公顷 | 2026-9 |
| 1995/1996 | 1.305 | 吨/公顷 | 2026-9 |
| 1994/1995 | 1.318 | 吨/公顷 | 2026-9 |
| 1993/1994 | 1.18 | 吨/公顷 | 2026-9 |
| 1992/1993 | 1.104 | 吨/公顷 | 2026-9 |
| 1991/1992 | 1.283 | 吨/公顷 | 2026-9 |
| 1990/1991 | 1.408 | 吨/公顷 | 2026-9 |
| 1989/1990 | 1.512 | 吨/公顷 | 2026-9 |
| 1988/1989 | 1.306 | 吨/公顷 | 2026-9 |
| 1987/1988 | 1.429 | 吨/公顷 | 2026-9 |
| 1986/1987 | 2.136 | 吨/公顷 | 2026-9 |
| 1985/1986 | 1.524 | 吨/公顷 | 2026-9 |
| 1984/1985 | 1.773 | 吨/公顷 | 2026-9 |
| 1983/1984 | 1.429 | 吨/公顷 | 2026-9 |
| 1982/1983 | 1.708 | 吨/公顷 | 2026-9 |
| 1981/1982 | 1.601 | 吨/公顷 | 2026-9 |
| 1980/1981 | 1.608 | 吨/公顷 | 2026-9 |
| 1979/1980 | 1.711 | 吨/公顷 | 2026-9 |
| 1978/1979 | 1.594 | 吨/公顷 | 2026-9 |
| 1977/1978 | 1.573 | 吨/公顷 | 2026-9 |
| 1976/1977 | 1.534 | 吨/公顷 | 2026-9 |
| 1975/1976 | 1.425 | 吨/公顷 | 2026-9 |
| 1974/1975 | 1.338 | 吨/公顷 | 2026-9 |
| 1973/1974 | 1.477 | 吨/公顷 | 2026-9 |
| 1972/1973 | 1.534 | 吨/公顷 | 2026-9 |