Year kg per hectare 1961 1059.852321783731 1962 1082.1638176900274 1963 1121.4364445807942 1964 1133.5025578878935 1965 1055.6617894087276 1966 1068.532543702946 1967 1177.0681485537423 1968 1180.0759254850154 1969 1224.6780104961913 1970 1276.2819290700195 1971 1312.7225278194308 1972 1292.4384081558935 1973 1314.2793269992828 1974 1327.9229590579428 1975 1450.6879141278755 1976 1439.1409292741678 1977 1523.2757365554617 1978 1586.9115343652436 1979 1515.8815811755667 1980 1619.4110087818415 1981 1720.7394169646805 1982 1697.9380089259073 1983 1762.4433668850525 1984 1793.5101169233292 1985 1839.4916561147354 1986 1869.1188427277498 1987 1854.4526020116884 1988 1972.0801496740503 1989 2013.2148259618607 1990 2074.46027654574 1991 2120.4020712059105 1992 2186.2310584293186 1993 2285.7618864947553 1994 2253.966735271744 1995 2251.703182499771 1996 2324.4667706677265 1997 2372.159852039559 1998 2441.171737296361 1999 2468.9504633419588 2000 2547.2955297369163 2001 2577.2159858235154 2002 2544.9536690602963 2003 2643.0568073297354 2004 2664.1573949112585 2005 2770.3803528301496 2006 2801.6462631704712 2007 2888.5331606909717 2008 2956.210668652964 2009 2939.1043162814726 2010 3027.812122380526 2011 3128.176994008722 2012 3193.5426719092357 2013 3262.9580475335188 2014 3271.9641014389936 2015 3274.5622526312236 2016 3347.2609953360743 2017 3480.768603404812 2018 3515.0569657920914 2019 3618.2585795761015 2020 3621.609254256984 2021 3673.1692609510064 2022 3741.6683834492305