Year	kilograms per hectare of arable land
1963	1.2954026670938288
1964	1.2227367858574163
1965	1.4221835588370368
1966	1.7705392535501778
1967	2.4035585331571463
1968	2.4082311923246547
1969	2.884921324691879
1970	3.0957344954522195
1971	3.5124225401054034
1972	4.2892350902550795
1973	4.348129749403634
1974	4.346745153493266
1975	5.409043688804181
1976	5.770723784054273
1977	6.805919010849864
1978	6.803876564184663
1979	7.871110030564045
1980	8.113934820998555
1981	8.478462504629555
1982	9.396152322414562
1983	9.925724025074727
1984	10.626776868014204
1985	10.307311335554887
1986	10.672580097910911
1987	10.981827526017756
1988	11.276362925205968
1989	12.262592483120525
1990	12.215596603809935
1991	12.93180738402121
1992	13.27544969338826
1993	12.430975870783232
1994	14.264759847426745
1995	15.802046766228358
1996	15.492292087068412
1997	15.297477334667807
1998	14.81265874942346
1999	16.39175760150248
2000	15.948596193980467
2001	16.139884310222705
2002	17.502700864393272
2003	13.950214600960559
2004	16.17007939816019
2005	15.92604486108852
2006	15.700561039990811
2007	15.964963934619183
2008	16.682244824382728
2009	16.309531147084577
2010	18.868151668832187
2011	21.089660616644274
2012	21.710079803451293
2013	20.740049734328604
2014	23.562785631437023
2015	24.206449048977433
2016	25.624998244251813
2017	28.096973824106286
2018	28.850956458652085
2019	30.62942269763213
2020	33.82181623970156
2021	33.39904019388777