Year kg per hectare 1961 1271.9292148215693 1962 1334.1793412716002 1963 1308.5598260292709 1964 1387.8255058482926 1965 1361.9990060710904 1966 1366.0195205632888 1967 1429.0962394244636 1968 1347.1769773188746 1969 1412.7631241575925 1970 1533.1272381861666 1971 1494.774260717153 1972 1445.2893008340257 1973 1611.3525592903627 1974 1662.0510299055393 1975 1627.2303136478067 1976 1632.070087090323 1977 1695.087276038717 1978 1713.5377098978374 1979 1729.0443112354571 1980 1800.2253929133062 1981 1997.1831016994774 1982 1988.824496790627 1983 1984.8508007674075 1984 2097.1833780915176 1985 2140.7801440984076 1986 2036.938639627211 1987 2098.6164710770895 1988 2094.0745229018607 1989 2111.2236711979576 1990 2091.4144905007524 1991 2143.4612699442678 1992 2420.072554643125 1993 2525.0806383229015 1994 2431.4532083546246 1995 2566.427261227468 1996 2513.9048226222976 1997 2659.9165530820505 1998 2847.0293671838976 1999 2810.0091526102033 2000 2849.635258893517 2001 3042.4759151906906 2002 2940.039070819541 2003 3189.731503582188 2004 3188.4084414492745 2005 3206.2542412290168 2006 3265.4682106057166 2007 3540.6058866341214 2008 3656.8468359686067 2009 3334.0330155454126 2010 3853.3161217157585 2011 3809.498796607264 2012 3963.3385445876884 2013 4159.7679173834495 2014 4169.475381704208 2015 4353.657093136729 2016 4183.992339090743 2017 4680.83689906231 2018 4339.244457745625 2019 4851.894525942296 2020 4714.578938801408 2021 4433.533556484331 2022 4586.633974212447