Year kg per hectare 1961 1101.58649046739 1962 1159.7462803782466 1963 1221.4651305015748 1964 1256.739009339775 1965 1242.9184541644045 1966 1280.9445076740108 1967 1359.2772390430603 1968 1359.8437545393283 1969 1370.0329474695031 1970 1469.825971123904 1971 1507.8708431051837 1972 1483.7551555792409 1973 1529.9859253736836 1974 1584.4216639471447 1975 1671.0645526913656 1976 1675.4802180247034 1977 1695.7712945836806 1978 1804.8152978745804 1979 1832.7939554063626 1980 1874.793901741373 1981 1967.832460125186 1982 2044.4734150594954 1983 2131.606490298296 1984 2205.093925756809 1985 2175.164692072727 1986 2200.0832058823157 1987 2215.782860057338 1988 2268.255197409681 1989 2322.011363685669 1990 2405.34788471376 1991 2419.2067603050114 1992 2340.6554479642004 1993 2401.675343696404 1994 2335.1716184088127 1995 2377.1269145106535 1996 2479.6881124030597 1997 2530.918124889246 1998 2571.695601091717 1999 2626.731467445775 2000 2581.0506488016445 2001 2681.954926308575 2002 2670.2262754428407 2003 2679.014062267215 2004 2787.733886495127 2005 2780.5347049027487 2006 2873.490980513285 2007 2923.37762554968 2008 3072.1205887177794 2009 3054.7573769592755 2010 3080.160286516261 2011 3217.4006625168818 2012 3259.140443357128 2013 3338.3180248116355 2014 3373.356022239705 2015 3459.499662414252 2016 3449.522129640944 2017 3576.6497042136452 2018 3575.049917550392 2019 3678.1649706737785 2020 3654.155624716124 2021 3692.0493617189913 2022 3766.1938296449953