Year	kg per hectare
1961	1441.3
1962	1371.7
1963	1574.7
1964	1677.3
1965	1691.9
1966	1897.4
1967	1951.6
1968	1945.5
1969	1671.6
1970	1902.3
1971	1994.4
1972	1860.4
1973	1683.3
1974	1881
1975	1722.9
1976	1451
1977	2130
1978	1732.8
1979	2191.5
1980	2059.3
1981	2120.5
1982	2203.6
1983	2261.5
1984	2704.1
1985	2949.1
1986	3355.3
1987	3222.6
1988	3531.6
1989	3914.7
1990	3619.7
1991	4050.9
1992	4177.4
1993	4246
1994	4489.3
1995	4472.5
1996	4264.3
1997	4507.5
1998	5052
1999	4061.1
2000	4362.1
2001	4935.7
2002	5183.3
2003	5390
2004	5657.5
2005	5811.2
2006	5998.3
2007	5744.3
2008	5844.4
2009	5462.3
2010	6815.4
2011	6927.8
2012	6229.6
2013	6913.2
2014	6128.4
2015	7082.3
2016	6858.2
2017	6779.4
2018	7144.3
2019	7157.2
2020	6245.8
2021	6491.2
2022	6113.9