Year	kg per hectare
1961	1244.7
1962	1206.7
1963	1249.7
1964	1199.6
1965	1143
1966	1139.9
1967	1235.3
1968	1286.7
1969	1303
1970	1278.2
1971	1270.2
1972	1286.5
1973	1306.3
1974	1352.2
1975	1396.8
1976	1582.8
1977	1550.8
1978	1409.5
1979	1282.7
1980	1241.7
1981	1561.6
1982	1962.7
1983	1675.9
1984	1343.1
1985	1633.8
1986	1886.2
1987	1568.5
1988	1745.6
1989	1723
1990	1561.8
1991	1712.4
1992	1661.1
1993	1461.2
1994	1918.2
1995	1753.1
1996	1402.6
1997	1397.2
1998	1590
1999	1427.7
2000	1375
2001	1639.6
2002	1488.3
2003	1594
2004	1805.7
2005	1646.1
2006	1646.4
2007	1773.1
2008	1417.5
2009	1242.8
2010	1710.1
2011	1514.6
2012	1744.8
2013	1661.5
2014	1583.4
2015	1772.7
2016	1383.1
2017	1426
2018	1709.2
2019	1608
2020	1842.6
2021	1487.7
2022	1448.5