Year	kg per hectare
1961	2013.8
1962	2217.1
1963	2017.9
1964	2010.6
1965	2052.9
1966	2030.8
1967	1898.5
1968	1531.3
1969	1688.9
1970	1887.2
1971	1821
1972	1971.2
1973	1821.1
1974	2421.4
1975	2173.2
1976	1760.5
1977	2577.5
1978	2633
1979	2651.9
1980	2953.3
1981	3116.3
1982	3060.8
1983	3221.5
1984	3078.7
1985	3261.5
1986	3247.1
1987	3189.2
1988	3006.5
1989	3320.7
1990	2980.4
1991	3285.6
1992	3438.1
1993	3258.4
1994	3664.2
1995	3899.1
1996	3958.1
1997	3964
1998	4003.3
1999	3791.2
2000	3799.2
2001	3947.9
2002	4084
2003	4155.5
2004	4216.6
2005	3861.4
2006	4523
2007	4222.2
2008	4161.5
2009	4345.5
2010	4165.4
2011	4343.9
2012	4465.4
2013	4936.7
2014	5210.7
2015	5476.9
2016	5395.5
2017	5523.4
2018	5696.2
2019	5831
2020	5633.5
2021	5442.6
2022	5940.7