Year	kg per hectare
1961	854
1962	1359.1
1963	1437.5
1964	1361.9
1965	1454.2
1966	1070
1967	1067.1
1968	958.6
1969	995.1
1970	1122.1
1971	1074.4
1972	1066.9
1973	1049.1
1974	936
1975	1074.8
1976	1097.4
1977	1110.1
1978	1114.5
1979	1086.3
1980	1211.9
1981	1105.3
1982	1199.1
1983	1157.7
1984	1065.5
1985	1226.3
1986	1243.8
1987	1282.9
1988	1216.2
1989	1154.6
1990	1042.6
1991	1237.2
1992	951.1
1993	1446.1
1994	1028.7
1995	1139.5
1996	1263
1997	1129.1
1998	972.6
1999	824.8
2000	848.3
2001	913
2002	1028.4
2003	941.9
2004	959.3
2005	1183.6
2006	1137.9
2007	1015
2008	1266.5
2009	1734.1
2010	1965.8
2011	2089.4
2012	2113.5
2013	2129
2014	1408
2015	1428.8
2016	1446.7
2017	1387.1
2018	1441.4
2019	1443.2
2020	1473.6
2021	1519
2022	1510.7