Year	kilograms per hectare of arable land
1961	3.4384615384615387
1962	2.7714285714285714
1963	2.8620689655172415
1964	3.2333333333333334
1965	2.9411764705882355
1966	2.857142857142857
1967	3.5294117647058822
1968	3.888888888888889
1969	3.8313513513513513
1970	6.110555555555556
1971	7.724102564102564
1972	6.6715
1973	7.99609756097561
1974	5.185365853658537
1975	7.5105
1976	13.449
1977	11.746
1978	14.082926829268292
1979	12.314146341463415
1980	17.507368421052632
1981	17.078
1982	15.380952380952381
1983	21.5005
1984	21.840975609756097
1985	14.27658536585366
1986	17.432093023255813
1987	22.513023255813952
1988	23.826046511627908
1989	24.90909090909091
1990	21.333333333333332
1991	29.78723404255319
1992	32.08695652173913
1993	32.17391304347826
1994	10.134761904761906
1995	18.921304347826087
1996	24.25
1997	23.183673469387756
1998	19.307692307692307
1999	18.555555555555557
2000	18.105818181818183
2001	9.64280701754386
2002	29.713684210526317
2003	31.077333333333332
2004	34.406
2005	30.491875
2006	36.82454545454546
2007	37.92606060606061
2008	34.8704347826087
2009	30.845714285714287
2010	37.398
2011	30.366285714285713
2012	26.39718
2013	29.257991537376586
2014	39.7649986114968
2015	41.99914387308534
2016	23.768987068965522
2017	33.993737722325456
2018	34.31702589589327
2019	30.247640536358947
2020	98.14007880020337
2021	96.73588249999999