Year kg per hectare 1961 1234.8260173042195 1962 1339.8163154897077 1963 1440.8202058523398 1964 1503.372639163611 1965 1567.1792485978367 1966 1660.2542762063788 1967 1726.585343631215 1968 1685.3709210419552 1969 1710.0651024892186 1970 1871.4529042953309 1971 1930.3867320605389 1972 1880.3694522246944 1973 1982.9816475622706 1974 2082.9034512130065 1975 2132.7854235232653 1976 2165.658042390668 1977 2162.1218752945165 1978 2347.512855990034 1979 2473.7451100975204 1980 2465.844677130039 1981 2618.1975559011184 1982 2777.648093878405 1983 2877.360166476641 1984 3063.690889988912 1985 2978.2912823091883 1986 3013.416815325373 1987 3073.486343705321 1988 3065.390075383038 1989 3141.070813909128 1990 3315.42819722991 1991 3305.428029667193 1992 2844.75679188421 1993 2885.657598426547 1994 2826.531717908252 1995 2909.9856260980873 1996 3084.1283365491126 1997 3171.3081784343867 1998 3281.8432817784937 1999 3311.24402668705 2000 3197.1289297356307 2001 3298.663870943723 2002 3321.9728634824305 2003 3345.191683367486 2004 3480.6924100347146 2005 3520.388813359618 2006 3630.6135097668994 2007 3683.6614075927714 2008 3899.902485471797 2009 3827.486808011403 2010 3948.83469901856 2011 4085.1844634116524 2012 4105.232021427064 2013 4248.317503786356 2014 4281.67749443069 2015 4417.355905929804 2016 4416.843788708398 2017 4628.574602379094 2018 4525.2901571365655 2019 4645.492379667381 2020 4649.020921217622 2021 4574.538004825028 2022 4768.962465543742