Year kg per hectare 1961 1107.551311955613 1962 1238.671911158814 1963 1415.9274023709238 1964 1274.5789736177753 1965 1308.1596741866886 1966 1520.630110166182 1967 1541.2308822116433 1968 1392.4300563518589 1969 1507.7648921628095 1970 1488.9224712645 1971 1803.2263158513265 1972 1762.6903820598648 1973 1564.464564437302 1974 1559.4037151412974 1975 1890.0851108030545 1976 2091.1837322952974 1977 2028.7138870918168 1978 2068.5757730231926 1979 2154.3026814781456 1980 2112.027494398259 1981 2169.189036173898 1982 2356.1670111511294 1983 2118.7929296727143 1984 2322.990161663005 1985 2066.1178593881823 1986 2401.6238758385907 1987 2346.776579950999 1988 2453.272320686899 1989 2128.464225502272 1990 2449.0455136939772 1991 2479.1138017975177 1992 1896.7973335426695 1993 1845.2492831794148 1994 1619.2430050261648 1995 1518.8219375290173 1996 1540.9696805996275 1997 1878.1732878069965 1998 1624.6927596215692 1999 1722.1642893878402 2000 1730.5560356565409 2001 2056.095935973983 2002 2104.476483927764 2003 1922.3541574180497 2004 2117.9657037591173 2005 2097.8370969928724 2006 2146.2182417521703 2007 2079.857437325536 2008 2505.8841122074195 2009 2432.2530214620547 2010 2155.6866174893844 2011 2648.892971355611 2012 2231.408542277495 2013 2669.031874135547 2014 2795.5421438515914 2015 2777.7796804073732 2016 2965.3290304506245 2017 3043.3215173430353 2018 2996.7952909916253 2019 3064.9718617647445 2020 3051.23283390206 2021 3094.2875892799434 2022 3279.5456967200107