Year	kilograms per hectare of arable land
1961	0.5020686843982473
1962	0.5276532743829476
1963	0.6788837396735845
1964	0.6506084862683847
1965	0.7895963486874049
1966	1.0033881897386254
1967	1.2347008440913605
1968	1.10491452991453
1969	1.1286663820964693
1970	1.4328636903751486
1971	1.5088963581979093
1972	1.8276136781468317
1973	1.915830291970803
1974	2.53377414356504
1975	3.1497984944110713
1976	3.5641979959315906
1977	4.2552109274771714
1978	3.7690918666766984
1979	4.380851228777424
1980	4.798233516241674
1981	5.9035569736181275
1982	5.490621396353657
1983	6.539714342091283
1984	6.940080432832798
1985	6.18406937114425
1986	6.225121367913045
1987	5.886652497040069
1988	6.920546515890697
1989	7.3385211277488525
1990	7.706594129415956
1991	7.914817542684968
1992	8.138479325530339
1993	8.465479354047424
1994	6.645177926766374
1995	5.35357707963426
1996	5.369891763152309
1997	5.8163917970984045
1998	5.966815723944027
1999	6.141052645362564
2000	5.8320460920254025
2001	5.971987348148044
2002	5.9535351868096305
2003	6.451521657741555
2004	6.2818464642815615
2005	6.629804428143672
2006	8.554399303212529
2007	5.631695263568068
2008	6.10091351248532
2009	6.189579390506906
2010	9.802450540978985
2011	6.633014325172348
2012	8.981645911723753
2013	9.202907447112496
2014	9.201659528898356
2015	9.96723701088421
2016	12.129028130614417
2017	15.620488812462575
2018	14.99220455874204
2019	16.81563548080818
2020	17.08259957168234
2021	15.443303883479743