Year	kg per hectare
1961	2791.8
1962	2071.3
1963	2578.1
1964	2595.4
1965	2553.6
1966	2169.2
1967	2729.1
1968	3524.9
1969	2625
1970	3206.9
1971	3226.3
1972	2981.7
1973	3260.2
1974	3777.8
1975	2556.6
1976	2840.7
1977	3566.5
1978	3677.3
1979	3557.6
1980	3644.8
1981	3698.7
1982	3746.8
1983	3335.5
1984	4284.6
1985	3885.9
1986	3251.6
1987	3814
1988	3104.8
1989	3408.9
1990	4399.3
1991	4015.5
1992	2810.5
1993	3923.4
1994	3129.6
1995	3629.3
1996	4026.3
1997	3885.9
1998	4044.9
1999	3709.5
2000	3930.9
2001	3709.5
2002	3495.2
2003	3940.7
2004	4400.6
2005	3992.9
2006	3674.5
2007	3855
2008	4488.1
2009	3446.3
2010	4004.2
2011	3436.9
2012	3686.8
2013	3374.3
2014	4363.4
2015	4803
2016	4651.6
2017	4561.4
2018	2656.2
2019	4709.8
2020	4683.8
2021	4183.7
2022	4728