Year	kg per hectare
1961	2200
1962	2200
1963	2340
1964	2700
1965	2666.7
1966	2500
1967	2500
1968	2800
1969	3100
1970	2300
1971	2500
1972	3000
1973	3000
1974	3000
1975	3000
1976	3000
1977	3000
1978	3000
1979	3000
1980	3000
1981	3000
1982	3000
1983	3666.7
1984	3500
1985	3400
1986	2857.1
1987	2500
1988	2222.2
1989	2000
1990	2100
1991	1573.9
1992	1613.9
1993	1653.8
1994	1693.7
1995	1733.7
1996	1773.6
1997	1813.5
1998	1853.5
1999	1893.4
2000	1916.6
2001	1958.4
2002	2000
2003	2026.4
2004	2061.5
2005	2097.5
2006	2000
2007	2333.3
2008	2271.1
2009	2313.7
2010	2356.2
2011	2398.7
2012	2500
2013	2500
2014	2539.5
2015	2585.5
2016	2606.5
2017	2648