Year	kg per hectare
1961	868.3
1962	1042.2
1963	1105.7
1964	1227.3
1965	1244.8
1966	1065.8
1967	1221.2
1968	932.9
1969	1236.4
1970	1368
1971	1282.8
1972	1106.2
1973	1158
1974	1552.6
1975	1871.1
1976	1844.4
1977	2156.8
1978	1699.7
1979	1560.1
1980	1785.2
1981	1655.2
1982	1569
1983	1907.9
1984	2041.5
1985	1856.8
1986	1359
1987	1355.8
1988	1603.1
1989	1295.7
1990	1115.7
1991	1285.1
1992	1493.5
1993	1572.8
1994	1405.8
1995	1362.3
1996	1374.5
1997	1159.8
1998	1149.6
1999	1220.5
2000	1146.8
2001	1209.1
2002	1179.8
2003	1230.3
2004	1185.4
2005	1255.9
2006	1228.9
2007	1222.2
2008	1294.2
2009	1315.7
2010	1266.9
2011	1356.4
2012	1282.8
2013	1200.3
2014	1138.7
2015	1143.1
2016	1090.1
2017	1162.5
2018	1148.5
2019	1125.8
2020	1114.3
2021	1118
2022	1163