Year	kg per hectare
1961	1082.5
1962	1278.7
1963	1303.1
1964	1178.5
1965	1250.7
1966	1327.6
1967	1480.6
1968	1569.1
1969	1558.1
1970	1380.3
1971	1840.5
1972	1611.1
1973	1595.1
1974	1765.6
1975	1974.3
1976	1766.2
1977	1925.2
1978	2174.7
1979	1907.8
1980	2479.9
1981	1571.3
1982	1764.3
1983	1851.1
1984	2772.1
1985	2762.2
1986	2143.1
1987	2626.8
1988	3017.9
1989	2491.5
1990	2482.7
1991	2488.9
1992	1955
1993	2717.4
1994	2348.3
1995	1729.7
1996	3303
1997	2764.4
1998	3395.9
1999	2705.2
2000	3603.3
2001	2804.7
2002	3222
2003	3250.7
2004	3750.1
2005	2159.3
2006	3028.2
2007	3933.9
2008	3573.5
2009	2944.8
2010	3291.5
2011	3691.8
2012	2842.5
2013	4047.1
2014	3248.5
2015	3243.1
2016	3877.8
2017	2770.2
2018	4205.5
2019	3445.5
2020	4501.5
2021	4227.4
2022	3307.4