Year	kg per hectare
1961	666.7
1962	833.3
1963	833.3
1964	892.9
1965	909.1
1966	914.9
1967	937.5
1968	940
1969	980
1970	980.8
1971	990.7
1972	991
1973	1000
1974	1000
1975	1009.9
1976	1021.2
1977	1030.6
1978	1158.7
1979	1142.9
1980	1141.3
1981	1142.9
1982	1165.4
1983	1250
1984	1333.3
1985	1344.3
1986	1344.3
1987	1363.6
1988	1400
1989	1400
1990	1500
1991	1666.7
1992	1666.7
1993	1600
1994	1793.1
1995	1793.1
1996	1793.1
1997	1740
1998	1984.2
1999	2165.7
2000	2476.2
2001	3000
2002	3050
2003	3400
2004	3550
2005	3600
2006	3800
2007	4000
2008	4761.9
2009	6000
2010	7533.3
2011	7308.5
2012	7340.4
2013	7413.2
2014	7516.2
2015	8342.3
2016	7709.5
2017	7820.7
2018	7862.8
2019	7437.7
2020	7445.5
2021	7477.3
2022	7424.3