Year	kg per hectare
1961	550.7
1962	381.7
1963	353.5
1964	1010.7
1965	1024.6
1966	446.3
1967	758.8
1968	395.9
1969	910.4
1970	226.5
1971	657.3
1972	864.2
1973	425.2
1974	915.4
1975	363.7
1976	422.9
1977	432.6
1978	369.1
1979	151.3
1980	932.7
1981	477.8
1982	478.6
1983	829.2
1984	538.1
1985	615.2
1986	617.7
1987	918.6
1988	1010.6
1989	914.5
1990	1220
1991	937.7
1992	1197.5
1993	1370.4
1994	1246.9
1995	1186.4
1996	1325.3
1997	899.7
1998	1038.3
1999	1841.8
2000	1205.8
2001	1097.8
2002	1145.1
2003	1237.2
2004	966.3
2005	1087.7
2006	748.6
2007	710.4
2008	698.4
2009	858.9
2010	1355.9
2011	1555
2012	1323.1
2013	1446.9
2014	1315.9
2015	1115.3
2016	1274.9
2017	1309.6
2018	1221.7
2019	1354.3
2020	1858.1
2021	1532
2022	1195.4