Year kg per hectare 1961 2021.4162472871255 1962 2195.363087900595 1963 2278.5618473300087 1964 2206.13324530903 1965 2375.216513758366 1966 2409.998758104038 1967 2499.6569241920906 1968 2558.155059922601 1969 2669.246239516525 1970 2568.5294702857414 1971 2925.8858251446422 1972 2936.53220181818 1973 2918.253841132422 1974 2736.5923582084442 1975 2912.666581758924 1976 2920.1775950276738 1977 3020.728420183971 1978 3317.0953905840806 1979 3367.141041494865 1980 3153.821988307754 1981 3358.1657401923567 1982 3478.0796187995857 1983 3072.892469634369 1984 3640.4606826785125 1985 3723.520656543776 1986 3721.374267771382 1987 3694.4995256465254 1988 3345.4333243415754 1989 3663.2957684741205 1990 3877.110988147898 1991 3837.232292852508 1992 4024.2084027406127 1993 3693.6711373856933 1994 4154.097492268868 1995 3812.6599160008086 1996 4167.74515293449 1997 4185.8463100360095 1998 4375.869195953917 1999 4364.935797725334 2000 4426.966183050465 2001 4335.781731272911 2002 4317.878444960917 2003 4251.164117719825 2004 4958.0949666080205 2005 4665.517113161628 2006 4610.622245460227 2007 4716.960328994825 2008 4892.822277077543 2009 5081.455698214172 2010 4986.906367526006 2011 5035.916704133312 2012 4728.272314395981 2013 5350.760066421725 2014 5561.70132027249 2015 5448.500020474601 2016 5862.864737285738 2017 5764.966499624559 2018 5562.405162127689 2019 5639.4219418721095 2020 5694.872887547448 2021 5667.994107837404 2022 5668.8141204263065