Year	kg per hectare
1961	1782.4
1962	1600.1
1963	1717.3
1964	1607.3
1965	1900.1
1966	1884.7
1967	1934.3
1968	2121.9
1969	2142.5
1970	1948.4
1971	2351
1972	2404.6
1973	2650.6
1974	2840.9
1975	2487
1976	2685.6
1977	2424.3
1978	2742.6
1979	2202.9
1980	2336.8
1981	2494.3
1982	2615
1983	2726.4
1984	2989.6
1985	2893.5
1986	3039.1
1987	3108.8
1988	2903.7
1989	3218.2
1990	3283.8
1991	3190.8
1992	2399
1993	2753
1994	2566.1
1995	3022.4
1996	2901.1
1997	2854.1
1998	3071
1999	2959.4
2000	2534.8
2001	3056.4
2002	3240.8
2003	2865.4
2004	3537.6
2005	3233.1
2006	2598.2
2007	3249.5
2008	3217.2
2009	3475.1
2010	3584
2011	3430.4
2012	3704.9
2013	3804.4
2014	4268
2015	3727.8
2016	4033.5
2017	4199.6
2018	3366.7
2019	3605.3
2020	4691.7
2021	4562.5
2022	4861.5