Year hectares 1961 267000 1962 267000 1963 267000 1964 266000 1965 265000 1966 266000 1967 267000 1968 268000 1969 278000 1970 278000 1971 239000 1972 239000 1973 226000 1974 196000 1975 192000 1976 195000 1977 196000 1978 192000 1979 195000 1980 210000 1981 230000 1982 250000 1983 270000 1984 280000 1985 300000 1986 320000 1987 340000 1988 360000 1989 380000 1990 400000 1991 410000 1992 420000 1993 431000 1994 450000 1995 450000 1996 450000 1997 450000 1998 450000 1999 450000 2000 450000 2001 450000 2002 450000 2003 450000 2004 450000 2005 450000 2006 450000 2007 450000 2008 450000 2009 450000 2010 450000 2011 450000 2012 450000 2013 450000 2014 450000 2015 450000 2016 450000 2017 450000 2018 450000 2019 450000 2020 450000 2021 450000