Year	kg per hectare
1961	1765.4
1962	1869.1
1963	1848.4
1964	1917
1965	1681.6
1966	1732.9
1967	2038.5
1968	2283.1
1969	2426.8
1970	2154.7
1971	1939.2
1972	1966.8
1973	1843.5
1974	1885.8
1975	1752.8
1976	1812.1
1977	2022.8
1978	2144.1
1979	2337.7
1980	2501.1
1981	2547.9
1982	2755.3
1983	3065.6
1984	2632.8
1985	2960.6
1986	2990.5
1987	2997.4
1988	2917.1
1989	2880.8
1990	2965
1991	2925.8
1992	2957.7
1993	3024.2
1994	2902
1995	3052.6
1996	3008.5
1997	3143.2
1998	3400.1
1999	3192
2000	3338.2
2001	3424.9
2002	3405.1
2003	3282.6
2004	3563.7
2005	3467.2
2006	3579.8
2007	3727.9
2008	3616.7
2009	3790.6
2010	3974.3
2011	3520.8
2012	3582.9
2013	3833.5
2014	3801.9
2015	3946.6
2016	3845.3
2017	3054.6
2018	3777.1
2019	4737.4
2020	4746.8
2021	4557.2
2022	3046.9