Year	kg per hectare
1961	3383.5
1962	3750.6
1963	3505.7
1964	3963.4
1965	3890.6
1966	3714.4
1967	3756.9
1968	4026.4
1969	3975.6
1970	3583.8
1971	3999.7
1972	3977.2
1973	3765
1974	4190.1
1975	3635.7
1976	3302.4
1977	4050.9
1978	4060.5
1979	4156.1
1980	3892.5
1981	4071.4
1982	4521.3
1983	3757.5
1984	5555.4
1985	4970.8
1986	5049
1987	4792.6
1988	5084.2
1989	5632.3
1990	6117.9
1991	5911.6
1992	4314.2
1993	5677.6
1994	5530.6
1995	6291.2
1996	6052.6
1997	6207.2
1998	6100.1
1999	5862.1
2000	6216
2001	6126.6
2002	5761.8
2003	6096.6
2004	6013.1
2005	6153.4
2006	5778.4
2007	5675.8
2008	6017.4
2009	6779
2010	5875.9
2011	5886.5
2012	6309.7
2013	6316.6
2014	6752.1
2015	6884.7
2016	6222
2017	6916.5
2018	4888.8
2019	6928.9
2020	6926.3
2021	6355
2022	7241.4