Year	kg per hectare
1961	654.8
1962	1157.6
1963	1121.3
1964	802.9
1965	1598.9
1966	752.4
1967	1297.7
1968	824.8
1969	1334.9
1970	657.3
1971	1336.3
1972	1068.3
1973	107.2
1974	1290.8
1975	1475.3
1976	1462.9
1977	1315
1978	1777.3
1979	1665
1980	1939.4
1981	1773.3
1982	1778.2
1983	1388.8
1984	1757.7
1985	2097.7
1986	1301.1
1987	2331.3
1988	2679.9
1989	2480.4
1990	1886
1991	1335.9
1992	2789.8
1993	2964.4
1994	2553.5
1995	2384.9
1996	2395.5
1997	1110.6
1998	1113.9
1999	2156.4
2000	931.4
2001	2275.9
2002	2394.4
2003	2263.9
2004	1677.9
2005	1205.6
2006	1219.7
2007	1596.1
2008	176.3
2009	1823.8
2010	1998.4
2011	1954.4
2012	2399.3
2013	1688
2014	291
2015	2683
2016	436.3
2017	1802.7
2018	1052.9
2019	2656.3
2020	2381.4
2021	2063.5
2022	2494.7