Year	kg per hectare
1961	1739.1
1962	1833.3
1963	1920
1964	2000
1965	2074.1
1966	2210.1
1967	1085.7
1968	2341
1969	1388.7
1970	2726
1971	2626.6
1972	3344.3
1973	3093.9
1974	3096.4
1975	2065.1
1976	2952.2
1977	3231.4
1978	2875.7
1979	3411.4
1980	3684.7
1981	3441.5
1982	3302.4
1983	3693.4
1984	2917.8
1985	2743.8
1986	2760.1
1990	4918.9
1991	4823.7
1992	4728.4
1993	4633.1
1994	4537.9
1995	4442.6
1996	4533.7
1997	3854.4
1998	3939.4
1999	4500
2000	4649.5
2001	4649.6
2002	4598.4
2003	3207.6
2004	3125
2005	3000
2006	3350.5
2007	3001.1
2008	2545.5
2009	2272.7
2010	2091.5
2011	2248.5
2012	2151.7
2013	2039
2014	1914
2015	1879.7
2016	1936.2
2017	1873.3
2018	1905
2019	1909
2020	1889.9
2021	1899.8
2022	1903.1