Year	kg per hectare
1961	1346.3
1962	1381.5
1963	1322.4
1964	1256.4
1965	1428.3
1966	1321.3
1967	1402.2
1968	1350.5
1969	1302.8
1970	1408.8
1971	1290.8
1972	1299.7
1973	1411.7
1974	1455.8
1975	1358.8
1976	1444.6
1977	1452.5
1978	1210.1
1979	1301.3
1980	1575.7
1981	1611.1
1982	1544.8
1983	1614.6
1984	1677.3
1985	1827.8
1986	1664.7
1987	1882.1
1988	1858.8
1989	1999.7
1990	1755.1
1991	1850.7
1992	2142.5
1993	2354.6
1994	2285
1995	2513.1
1996	2422.2
1997	2521.8
1998	2580.4
1999	2732
2000	2643.3
2001	3147.6
2002	2844.8
2003	3385.4
2004	3131.8
2005	2882.6
2006	3210.5
2007	3553.1
2008	3831.3
2009	3532.1
2010	4040.6
2011	4037.5
2012	4584.5
2013	4826.4
2014	4640.4
2015	5000.6
2016	4181.7
2017	5209.6
2018	4806.5
2019	5321.4
2020	5255.4
2021	4477.4
2022	4901.1