Year	kilograms per hectare of arable land
1961	3.1985914884424282
1962	3.517666315311378
1963	4.044478540537351
1964	4.332639635313041
1965	4.648424092596373
1966	5.221751464465976
1967	5.85820050963413
1968	6.030871544082112
1969	6.237313144191443
1970	7.029538848299159
1971	7.963326138203301
1972	8.749520586576423
1973	8.974223985643384
1974	9.52515944146321
1975	10.210778476473005
1976	10.606903043614684
1977	10.951708813003178
1978	10.927867930481064
1979	12.075644777232693
1980	13.701860566330279
1981	15.506596521833941
1982	14.61939383809683
1983	13.24381517580163
1984	13.40033727039411
1985	12.72902402918396
1986	12.256619533048339
1987	11.524937639490613
1988	13.10047694132058
1989	12.818765467290325
1990	12.945771775931055
1991	12.699873808188446
1992	12.560945967110415
1993	13.320607218083898
1994	11.934816025766153
1995	10.872726302558872
1996	12.144007357406862
1997	11.984856178499955
1998	11.435002118042773
1999	11.544908227173114
2000	11.076874309461907
2001	11.282535212951762
2002	12.352630985012853
2003	11.073402003211795
2004	11.4601948691847
2005	10.545293391380255
2006	12.623240397590779
2007	11.600786052505397
2008	11.82837190751039
2009	11.870187534817736
2010	14.335478200506527
2011	13.182425585597942
2012	14.135816561280773
2013	14.428831007203136
2014	14.936326552848405
2015	14.91458148995715
2016	16.91649949875984
2017	20.22032433187873
2018	19.654988861644398
2019	21.041795907575604
2020	23.65130530138661
2021	22.607775831876943