Year	kg per hectare
1961	3125.3
1962	2763.6
1963	2732.6
1964	3325.4
1965	3275.7
1966	3521.3
1967	3708.4
1968	3560.4
1969	3681.8
1970	2974.8
1971	3487.3
1972	3786.8
1973	3935.3
1974	3259.8
1975	3307.7
1976	4003.3
1977	4163
1978	4033.7
1979	3900
1980	3941.4
1981	4426.6
1982	4537.7
1983	4532.1
1984	4804.1
1985	4611.8
1986	4451.8
1987	4453.3
1988	4611.1
1989	4275.8
1990	5034
1991	5144.1
1992	5300.1
1993	5277.9
1994	5593.4
1995	5625.4
1996	5774.3
1997	5892.2
1998	6294.4
1999	6168.7
2000	6316.5
2001	6534.7
2002	6276.3
2003	7059.9
2004	6462.1
2005	7566.2
2006	7028.7
2007	7916.4
2008	7379.8
2009	6909.9
2010	7387.1
2011	6953.2
2012	8012
2013	8105.6
2014	8033.9
2015	8026.6
2016	8383.8
2017	8464.4
2018	8064.3
2019	8205.3
2020	9039.6
2021	8812
2022	8522