Year kg per hectare 1961 1388.350256933081 1962 1386.0261372605385 1963 1531.0079642470807 1964 1450.7551740763622 1965 1592.7606844580139 1966 1734.0203885732776 1967 1758.380805004811 1968 1707.0570941021458 1969 1779.5866635875905 1970 1678.8659501255208 1971 2067.242980443698 1972 2137.6831856672234 1973 2034.3938271262061 1974 2056.5502619904105 1975 2159.72792811739 1976 2458.6232281147204 1977 2323.3714409751756 1978 2419.5961318772715 1979 2330.2055758993865 1980 2361.676541983057 1981 2348.7112528029925 1982 2617.8481253729105 1983 2444.692986942272 1984 2684.4341177471347 1985 2503.7436811298267 1986 2730.8215075852136 1987 2650.450394806281 1988 2734.961806728992 1989 2611.215755850198 1990 2790.3678707677827 1991 2816.895278529197 1992 1947.800612957089 1993 1942.425008466508 1994 1756.15211172644 1995 1728.5352190950737 1996 1706.9462263391888 1997 2057.9219800882706 1998 1834.290383004254 1999 1929.2149688116278 2000 1821.6369765348588 2001 2205.8076736951302 2002 2228.2877359559184 2003 2040.0871502057207 2004 2350.7886209887324 2005 2269.162383641692 2006 2243.7374028057607 2007 2165.404710971648 2008 2614.3682821007383 2009 2548.2985850464474 2010 2342.8513354362494 2011 2781.6784218735847 2012 2360.994246795619 2013 2820.8213126827727 2014 2975.3759941312005 2015 2894.6941481584463 2016 3104.5446765990473 2017 3238.462113133434 2018 3188.350136911602 2019 3242.7527154263826 2020 3196.1554031303135 2021 3311.8529001932284 2022 3414.1629466919785