Year kg per hectare 1961 813.1626413639095 1962 1105.4056577767553 1963 1036.8661373356117 1964 991.5213549694604 1965 1030.6597575130563 1966 921.2080036401456 1967 1009.5183493163801 1968 1162.4898446383324 1969 1078.017919317645 1970 1018.5350908036907 1971 1101.7518977277246 1972 1228.1734827487842 1973 988.4636622143106 1974 1110.804967766152 1975 1148.1077002273364 1976 1240.852778069375 1977 1041.787175513345 1978 1186.9174403562797 1979 1143.2304159473485 1980 1240.0056918054931 1981 1141.685132102975 1982 1276.291320666696 1983 1157.3824066945651 1984 1213.1755550680323 1985 1348.180614697997 1986 1496.4414806552977 1987 1385.3995383322097 1988 1644.747609401736 1989 1392.0791949973714 1990 1566.0363476292725 1991 1761.5472509358133 1992 1652.8135827028464 1993 1708.7753072104138 1994 1965.02063878328 1995 1835.3576053138625 1996 2012.9050223829697 1997 1900.951703055658 1998 1972.1470911478423 1999 1933.6549108121308 2000 1817.5478486994737 2001 2023.8446356090815 2002 2324.3698205569294 2003 2387.457313892627 2004 2347.7749668643773 2005 2192.433753196541 2006 2482.946253723289 2007 2249.829021670611 2008 2174.083607765505 2009 2479.957723595591 2010 2272.5791739337214 2011 2300.4710831879497 2012 2264.6001120102637 2013 2436.298463715542 2014 2372.773976284302 2015 2672.2792283608833 2016 2559.4127948813907 2017 2393.3280653305746 2018 2419.719931664618 2019 2464.4884766781256 2020 2244.994494146276 2021 2425.1719361106398 2022 2382.0998107695254