Year kg per hectare 1961 1278.7212387659245 1962 1344.5803536940978 1963 1314.4651833325624 1964 1389.5189373928963 1965 1364.8509406881394 1966 1363.6696070316748 1967 1432.092237743113 1968 1345.359924143224 1969 1418.5303137965677 1970 1535.3985317870795 1971 1495.6048211809941 1972 1442.7849348912212 1973 1619.9139143333628 1974 1665.275238626035 1975 1632.9351617057232 1976 1644.1742678169055 1977 1690.5284932404288 1978 1714.2933142740346 1979 1718.7831858455986 1980 1793.9691818105694 1981 1998.8634512976198 1982 1985.2513535001137 1983 1982.8024868739524 1984 2089.9614962361215 1985 2133.140434509495 1986 2018.5683024014977 1987 2081.005922111749 1988 2065.122315350718 1989 2069.4164510821715 1990 2055.1813932611517 1991 2102.7764266685313 1992 2387.6697105705884 1993 2494.680542247046 1994 2390.0541999808197 1995 2524.892521580266 1996 2467.7885134321364 1997 2619.1631763059636 1998 2803.9847469585766 1999 2771.6742653736533 2000 2811.1579473634215 2001 3008.222500784416 2002 2897.1096767015615 2003 3154.029079322902 2004 3135.382778307047 2005 3152.190039286275 2006 3210.4945201011756 2007 3507.9066036642776 2008 3630.668485334688 2009 3299.9981726293304 2010 3823.525443367025 2011 3771.965471575855 2012 3942.1526082346345 2013 4140.160958328953 2014 4146.564494313454 2015 4341.779179371074 2016 4154.521250927187 2017 4676.024321928379 2018 4331.663650306486 2019 4843.945536253616 2020 4707.79024900249 2021 4414.611033461546 2022 4589.545627600322