Year	kg per hectare
1961	1104.9
1962	1124.5
1963	1130.1
1964	1302
1965	1335.6
1966	1290
1967	1371.4
1968	1430.4
1969	1492.7
1970	1540.8
1971	1530
1972	1513.6
1973	1501.6
1974	1613.8
1975	1745
1976	1729.8
1977	1779.4
1978	1918.5
1979	2009
1980	2191.1
1981	2292.5
1982	2415.5
1983	2183.7
1984	2340.5
1985	2431.1
1986	2332.4
1987	2321.8
1988	2180.5
1989	2198.2
1990	2424.4
1991	2426.9
1992	2708.2
1993	2639.4
1994	2518.3
1995	2519.6
1996	2552.9
1997	2678.7
1998	2639.3
1999	2708.1
2000	2760.9
2001	2855.2
2002	2913.1
2003	2964
2004	3078.6
2005	3130.8
2006	3213.3
2007	3353
2008	3452.3
2009	3433.7
2010	3501.2
2011	3240.5
2012	3453.4
2013	3386.9
2014	3581.9
2015	3470.1
2016	3748.8
2017	3799.7
2018	3826.3
2019	3992.4
2020	3806.5
2021	3878.9
2022	3981.3