Year kg per hectare 1961 1288.1950078203595 1962 1393.912448394578 1963 1525.2247495115241 1964 1612.131138915256 1965 1692.963408112101 1966 1776.7188781370987 1967 1828.5285259213852 1968 1849.8980988728788 1969 1859.2973367531395 1970 2051.8178591385604 1971 2088.3730223069215 1972 2026.0999097667564 1973 2163.012995410498 1974 2250.0183608548978 1975 2314.103414517396 1976 2367.274549102425 1977 2311.0078878075046 1978 2548.9026237516277 1979 2739.154605132585 1980 2705.3684194246907 1981 2834.632353318712 1982 3129.8782675809894 1983 3305.7728883065615 1984 3491.8746675070443 1985 3398.362551521583 1986 3458.045693594011 1987 3516.7513717890965 1988 3484.1865422833666 1989 3575.5480359050516 1990 3786.3883513467604 1991 3777.9243237812198 1992 3869.330334466032 1993 4007.429973694352 1994 3983.7009450701657 1995 4066.2820345313376 1996 4241.482077330493 1997 4193.671713740938 1998 4293.217595066821 1999 4288.008985294574 2000 4198.342829459664 2001 4249.174329840242 2002 4329.995099131822 2003 4330.556346452535 2004 4552.894759985952 2005 4607.209581425506 2006 4688.468336252735 2007 4717.3504614358735 2008 4899.306085966486 2009 4852.7748050624505 2010 4916.817500909998 2011 5058.149112088552 2012 5174.9564023008525 2013 5227.4945628970445 2014 5261.060983751747 2015 5361.987986452922 2016 5356.70607146512 2017 5414.716592754193 2018 5440.313129354389 2019 5534.695455341107 2020 5536.770840460975 2021 5575.739333775838 2022 5605.472401055992