Year	kg per hectare
1961	1675.5
1962	1737.2
1963	1891.8
1964	1830.1
1965	1786.3
1966	1842.8
1967	1775.8
1968	1821.9
1969	1905.2
1970	2075.8
1971	1993.2
1972	1781.4
1973	1957.8
1974	1878.8
1975	1889.4
1976	1899.5
1977	1592
1978	1968.7
1979	1837.9
1980	1911.1
1981	1983.4
1982	1918.9
1983	2050.5
1984	2102.6
1985	2125.4
1986	2089
1987	2006.3
1988	2203.5
1989	2143.1
1990	2009.2
1991	2295.4
1992	2254.1
1993	2119.9
1994	2409.4
1995	2507.4
1996	2525.7
1997	2456.4
1998	2522.6
1999	2537.4
2000	2719
2001	2952.6
2002	2998.3
2003	2998.8
2004	2961
2005	3046.8
2006	3009.5
2007	3089.4
2008	3063.5
2009	2995.9
2010	3071.3
2011	3257.2
2012	3256.6
2013	3214
2014	3141.1
2015	2958.7
2016	3064.5
2017	3172.3
2018	3151.7
2019	3022
2020	3013.9
2021	3061.9
2022	3092.5