Year	kg per hectare
1961	1319.2
1962	1317
1963	1370.6
1964	1350
1965	1373.4
1966	1362.6
1967	1361.2
1968	1139.5
1969	1327.5
1970	1277.3
1971	734.7
1972	714.2
1973	563.5
1974	730.2
1975	837.8
1976	659.1
1977	751.8
1978	744.6
1979	799
1980	587.6
1981	1071.8
1982	1864.9
1983	2764
1984	3235.1
1985	3471.1
1986	3840.3
1987	4106
1988	4127.2
1989	4086.7
1990	4244.8
1991	4200.7
1992	4191.6
1993	4462.4
1994	4546.5
1995	3784.4
1996	3429.5
1997	3562.8
1998	3540.5
1999	3575.5
2000	3516.4
2001	3932
2002	4047.6
2003	4228.9
2004	4675.2
2005	4753.2
2006	5047.1
2007	5121.8
2008	5221.3
2009	4874.4
2010	5507.8
2011	5483.3
2012	5164.2
2013	5359.8
2014	5192.8
2015	5582.8
2016	5440.9
2017	5630.9
2018	5605.5
2019	5295.4
2020	4819.4
2021	4727.5
2022	5002.1