Year	kg per hectare
1961	1587.2
1962	1513.9
1963	1598.1
1964	1594.3
1965	1602.6
1966	1512.8
1967	1514.9
1968	1503.6
1969	1502.3
1970	1465.5
1971	1463.6
1972	1511.1
1973	1534
1974	1494.3
1975	1396.4
1976	1486.7
1977	1511.7
1978	1503
1979	1554.4
1980	1525.4
1981	1456.5
1982	1500
1983	1523.8
1984	1545.6
1985	1453.2
1986	1473.8
1987	1580
1988	1615.1
1989	1459.4
1990	1588.2
1991	1701.5
1992	1550
1993	1588.5
1994	1658.4
1995	1557.7
1996	1591
1997	1562.4
1998	1583.7
1999	1599.1
2000	1630.3
2001	1541.5
2002	1449.4
2003	1538.1
2004	1559.8
2005	1569.9
2006	1580
2007	1667.1
2008	1611.4
2009	1589.1
2010	1595
2011	1596.1
2012	1600.6
2013	1600.4
2014	1592.5
2015	1591.7
2016	1590.2
2017	1587.6
2018	1587
2019	1587.5
2020	1587.6
2021	1587.6
2022	1587.4