Year	kg per hectare
1961	2097
1962	2058.1
1963	2143.8
1964	1986.5
1965	2144.2
1966	2129
1967	2015.5
1968	2164.2
1969	2318.1
1970	2383
1971	2468.6
1972	2396.1
1973	2632.2
1974	2826.6
1975	2641.2
1976	2697
1977	2611.7
1978	2542.8
1979	2822.8
1980	2835.9
1981	2824.4
1982	2742.9
1983	2579.9
1984	2497.9
1985	2642.4
1986	2619.4
1987	2450.9
1988	2505.6
1989	2601.9
1990	2740.3
1991	2787.4
1992	2953.1
1993	3003
1994	3031.9
1995	3119.2
1996	3200
1997	3023.3
1998	2843.2
1999	2910.3
2000	3039.5
2001	3108.1
2002	3232.1
2003	3347.2
2004	3314.9
2005	3407
2006	3383.6
2007	3540.6
2008	3599.2
2009	3734.7
2010	3659.9
2011	3780.2
2012	3866.7
2013	3948
2014	4652
2015	4054.2
2016	4013.2
2017	3797.4
2018	3816.8
2019	3552.2
2020	3706.4
2021	3824.3
2022	3749.6