Year	kg per hectare
1961	947.3
1962	929.7
1963	965.8
1964	993.6
1965	854.4
1966	864.2
1967	993.7
1968	1036.6
1969	1053.7
1970	1134.8
1971	1136.1
1972	1107.8
1973	1152.8
1974	1074.5
1975	1260.8
1976	1198.7
1977	1331.1
1978	1370.2
1979	1222.3
1980	1350
1981	1398.8
1982	1346.4
1983	1564.4
1984	1563.8
1985	1592.2
1986	1585.4
1987	1583.7
1988	1775.8
1989	1916.4
1990	1891.2
1991	1926.3
1992	2024.8
1993	2084.9
1994	2115.5
1995	2111.7
1996	2181
1997	2228.6
1998	2248.4
1999	2313.7
2000	2294.2
2001	2423.1
2002	2187.3
2003	2399.4
2004	2350
2005	2411.6
2006	2446.5
2007	2583.3
2008	2637.9
2009	2580.8
2010	2676.4
2011	2860.7
2012	2963.5
2013	2977.5
2014	2966.4
2015	2854
2016	2995.1
2017	3127.7
2018	3278.1
2019	3416.1
2020	3383.4
2021	3497.9
2022	3566.6