Year	kg per hectare
1961	2807.3
1962	2597.5
1963	2538.7
1964	2074.2
1965	2475.1
1966	2103.6
1967	2058.8
1968	2003
1969	1668.6
1970	2008.8
1971	2433.3
1972	2150.6
1973	2562
1974	2258
1975	1887.5
1976	1606.1
1977	1268.8
1978	1535.2
1979	2100.3
1980	2364.4
1981	1797.4
1982	1302.2
1983	2023.4
1984	1926
1985	2088
1986	2010.1
1987	1502.1
1988	1823.9
1989	2160.5
1990	2602.7
1991	2389.3
1992	2656
1993	2680
1994	2863.9
1995	2983.8
1996	3429.3
1997	4085.1
1998	3887.9
1999	3981.5
2000	4024.2
2001	4200
2002	4004.9
2003	3599.2
2004	3620.4
2005	3741
2006	3716.7
2007	3886.8
2008	3967.6
2009	4187.7
2010	4343.9
2011	4789.3
2012	4191
2013	4640.6
2014	4726.4
2015	4748.4
2016	4642.9
2017	4853
2018	4805.4
2019	4716
2020	4793.6
2021	4768.2
2022	4751.8