Year	kg per hectare
1961	940.6
1962	1211.3
1963	1220.9
1964	1360.2
1965	1304
1966	1319.9
1967	1327.8
1968	1318.8
1969	1600.4
1970	1357.5
1971	1288.7
1972	1356.7
1973	1346.5
1974	1381.1
1975	1476.2
1976	1427.1
1977	1441.6
1978	1438.1
1979	1238.4
1980	1251.1
1981	1256.3
1982	1309.5
1983	1243.9
1984	1536
1985	1253.7
1986	1477.5
1987	1283.8
1988	1222.9
1989	1238.1
1990	1201.7
1991	1233.7
1992	1234
1993	1187.8
1994	1161.1
1995	1195
1996	1253.3
1997	1205.6
1998	1111.6
1999	1118.9
2000	1078.2
2001	998.2
2002	995.9
2003	1011.8
2004	1000.3
2005	1117.8
2006	1347.6
2007	1290.4
2008	1350.9
2009	1645.9
2010	1747.2
2011	1751.1
2012	1539
2013	1777.5
2014	1519.7
2015	1339.7
2016	1092.3
2017	1141.7
2018	813
2019	1523
2020	1633.7
2021	1966.9
2022	1877.4