Year	kg per hectare
1961	989.4
1962	1136
1963	1343.4
1964	1117.9
1965	1138.6
1966	1272.7
1967	1303.4
1968	1215.7
1969	1291.7
1970	1215
1971	1573.5
1972	1435.1
1973	1238.1
1974	1294.2
1975	1632.4
1976	1805.5
1977	1791.7
1978	1824.6
1979	1880.1
1980	1855.1
1981	1871.7
1982	1978.7
1983	1838.4
1984	1971.1
1985	1931
1986	2135.5
1987	2137.4
1988	2250.2
1989	1742.1
1990	2214.2
1991	2240.5
1992	2124.4
1993	2255.9
1994	1922.3
1995	2057.3
1996	2112.3
1997	2151.3
1998	2387.5
1999	2099.8
2000	2370.6
2001	2178.3
2002	2242
2003	2308.6
2004	2477.9
2005	2634.4
2006	2661.9
2007	2410.2
2008	2601.3
2009	2808
2010	2727.1
2011	2970
2012	2958.3
2013	3256.9
2014	2831.5
2015	3307.8
2016	3105.4
2017	3257.4
2018	3163.9
2019	3200.8
2020	3341.5
2021	2918.5
2022	3464.7