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	14.613269633890704
1983	13.241083851548968
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	11.544843900014484
2000	11.076700543787082
2001	11.282485889716906
2002	12.352630985012853
2003	11.073332533836536
2004	11.46019733930159
2005	10.54516973680899
2006	12.62324881176001
2007	11.600691241479812
2008	11.828259943021775
2009	11.869991119822686
2010	14.335400216907985
2011	13.18221755670347
2012	14.135484651589678
2013	14.428606587679752
2014	14.936107377556766
2015	14.914040151278293
2016	16.916162375755416
2017	20.219910101057977
2018	19.654662780626268
2019	21.04125710451261
2020	23.650967041549354
2021	22.607437824158282