Year	kg per hectare
1961	214.7
1962	221
1963	255.3
1964	235
1965	341.9
1966	319.9
1967	292.4
1968	242.3
1969	326
1970	219.6
1971	229.8
1972	581.1
1973	627.1
1974	398
1975	472.4
1976	463
1977	286.8
1978	435.4
1979	351.7
1980	386.9
1981	550.2
1982	769.6
1983	756.9
1984	579.9
1985	595
1986	672.1
1987	620.8
1988	659.9
1989	665.7
1990	674.5
1991	701
1992	702.1
1993	696.5
1994	676.2
1995	679.1
1996	678
1997	836.9
1998	705.7
1999	652.1
2000	637.7
2001	619.4
2002	632.3
2003	620
2004	620
2005	622.8
2006	622.6
2007	623
2008	621.7
2009	634.1
2010	669.9
2011	664.5
2012	681.4
2013	663.8
2014	666.8
2015	665.3
2016	669.9
2017	676
2018	680.5
2019	668.8
2020	668.7
2021	669.4
2022	669.9