Year	kilograms per hectare of arable land
1961	1.719903846153846
1962	2.0550943396226415
1963	3.1241666666666665
1964	2.802636363636364
1965	3.014375
1966	5.87280701754386
1967	8.66801724137931
1968	8.415254237288135
1969	8.758333333333333
1970	6.588943089430894
1971	10.308020271900894
1972	12.159695817490494
1973	10.789280575539568
1974	13.756906455142232
1975	12.090536912751677
1976	15.635716169876023
1977	17.250998541811956
1978	17.873106530916314
1979	17.742261722341404
1980	16.659945504087194
1981	18.580124592109165
1982	18.70457584743299
1983	27.79737466026716
1984	25.613470490201713
1985	25.35460351551461
1986	31.555306007860754
1987	35.13106525376464
1988	43.46530911552347
1989	46.57431317900006
1990	59.665656796615984
1991	54.94574528840663
1992	64.84510964148973
1993	85.16242317822652
1994	79.63461763672561
1995	88.33528722157092
1996	88.23455643288435
1997	85.03186541884367
1998	93.06953209392233
1999	100.07538173355282
2000	88.31038189533238
2001	94.9414815650017
2002	100.00085484505935
2003	126.54421997755331
2004	111.82965553818669
2005	96.21217270194987
2006	99.81778922742716
2007	116.77180217330732
2008	110.61457226146429
2009	109.01374081039494
2010	143.26000114129195
2011	146.85671497033317
2012	145.30283731069298
2013	161.62068273366424
2014	156.7286069710128
2015	135.27451717816805
2016	146.95862927610125
2017	167.1548247447304
2018	138.424165874498
2019	112.36776547619046
2020	135.29766617699255
2021	139.36131253644314
