Year kg per hectare 1961 1120.8111086178724 1962 1169.9284281456528 1963 1232.7123342380016 1964 1266.1585185395083 1965 1263.6358695331899 1966 1302.223318231411 1967 1378.449207899802 1968 1380.9949571010147 1969 1389.5616884831024 1970 1479.1477339181442 1971 1531.9411682983675 1972 1516.470422978208 1973 1557.7005332258937 1974 1612.661834156791 1975 1690.4539520727478 1976 1706.4135676731398 1977 1720.980506627065 1978 1830.5416037563443 1979 1849.357655921354 1980 1893.7085825813228 1981 1979.6685362248827 1982 2068.371265611824 1983 2148.2020868681952 1984 2228.888525959516 1985 2196.8794613185873 1986 2223.88358428537 1987 2236.4518739503037 1988 2289.6555644189207 1989 2345.700208552678 1990 2426.4483261832047 1991 2436.2735735562346 1992 2335.2636350777293 1993 2402.713475158894 1994 2343.6156047223444 1995 2402.417609914436 1996 2494.1528321094147 1997 2556.481405749703 1998 2587.3295364586875 1999 2643.7074818426445 2000 2580.2210083321065 2001 2698.526455167008 2002 2683.8722166759353 2003 2685.3844265303032 2004 2821.439579385782 2005 2801.299714671684 2006 2878.9005336382215 2007 2924.639507023759 2008 3083.859620694401 2009 3066.6002290142264 2010 3098.00432488236 2011 3234.8800997578664 2012 3262.2197783725383 2013 3355.8674413391795 2014 3397.9846085765184 2015 3470.2657512198216 2016 3468.95574821279 2017 3604.5780966845045 2018 3600.450247600424 2019 3700.577076139202 2020 3672.8444044696157 2021 3724.445459703529 2022 3783.5842416454766