Year	kg per hectare
1961	784.8
1962	880.6
1963	828.6
1964	814.3
1965	855.7
1966	804.4
1967	1097.1
1968	1136.4
1969	953.4
1970	1038.3
1971	1321.1
1972	1148.5
1973	1158.8
1974	1130.4
1975	1137.5
1976	1082.4
1977	942.9
1978	890.8
1979	982.5
1980	1274.8
1981	1050
1982	1205.6
1983	1078
1984	1491.8
1985	1437.3
1986	1771.5
1987	1804.6
1988	1642
1989	2018
1990	1877.7
1991	2162.1
1992	1805.4
1993	2049
1994	2406.9
1995	2063.6
1996	2462.4
1997	2187.2
1998	2760.6
1999	2795
2000	2793.5
2001	2645.3
2002	2918.6
2003	2643.2
2004	2965.6
2005	2114
2006	3209
2007	3415.7
2008	3589.7
2009	3289.9
2010	3351.3
2011	4088.4
2012	4091.6
2013	4336.4
2014	4416
2015	4606.9
2016	4422.4
2017	4759.7
2018	4809
2019	5176.5
2020	4881.3
2021	5379.7
2022	5137.1