Year	kilograms per hectare of arable land
1964	1.7461444617390938
1965	1.7718517651191383
1966	1.9722087548174505
1967	2.5539304255406123
1968	2.7715168420881917
1969	3.0926347271689405
1970	3.3964814590646815
1971	4.137186607171519
1972	4.629861782061212
1973	5.005386671789207
1974	5.544919979142433
1975	6.207770121212607
1976	6.73780008028904
1977	6.801151246387427
1978	7.283688845090123
1979	8.905460236026748
1980	9.98923711275555
1981	10.200625702539755
1982	10.720912911217738
1983	11.093955625965632
1984	13.54064310909549
1985	14.382836781464855
1986	15.193430456940215
1987	15.939150455784231
1988	17.076270062342484
1989	15.718669576576788
1990	15.529397250345056
1991	14.449434175207418
1992	27.640618606330484
1993	20.416912447026696
1994	19.41928101753044
1995	17.131466891201057
1996	14.74928651197419
1997	15.252268475210476
1998	14.033982489617241
1999	13.901840250806123
2000	14.246110341127554
2001	15.300976695891658
2002	15.485434916530217
2003	11.980978320065207
2004	12.85199634356169
2005	13.418411941345687
2006	14.928686954302012
2007	15.380085538742184
2008	17.397911367256047
2009	15.562343406734891
2010	17.517152227282665
2011	17.953906242161942
2012	19.164097861104935
2013	18.30276929150926
2014	18.56095612578395
2015	17.49132640040775
2016	21.367959354834184
2017	25.591715298803454
2018	25.268730752402316
2019	25.646871632139252
2020	27.837742276597364
2021	26.509026382483142