Year	kg per hectare
1961	1251.8
1962	1309
1963	1273
1964	1309.1
1965	1347.8
1966	1130.9
1967	1329.8
1968	1061.7
1969	1235.6
1970	1266.2
1971	1257.4
1972	1117.2
1973	1363
1974	1414.5
1975	1373.3
1976	1410.9
1977	1418.9
1978	1341.3
1979	1495.7
1980	1582.2
1981	1527.8
1982	1480.3
1983	1501.8
1984	1442
1985	1748.3
1986	1678.9
1987	1998
1988	1926.6
1989	1765.9
1990	1979.3
1991	1649.7
1992	1753.3
1993	2009.7
1994	2174.8
1995	2092.3
1996	2227.5
1997	2416.1
1998	2037.8
1999	1951.2
2000	1980.3
2001	2160.3
2002	2090.4
2003	2323.5
2004	2461.8
2005	2167.9
2006	2343.8
2007	2698.8
2008	2681.3
2009	2357.4
2010	3456.9
2011	3481.8
2012	3035.7
2013	3683.2
2014	3276.7
2015	4148.9
2016	4425.5
2017	4446.5
2018	4225.7
2019	4601.1
2020	4706.5
2021	3823.1
2022	4294