Year	kilograms per hectare of arable land
1961	8.29983451180984
1962	8.834894991922456
1963	9.814834716072733
1964	10.698422537619699
1965	11.257809184279772
1966	10.93105952158669
1967	11.892627575801418
1968	13.953933307049034
1969	15.031716456534792
1970	16.867146718385705
1971	20.707170503157467
1972	22.58004228498484
1973	24.761519376181475
1974	25.493730221518987
1975	26.8963998237956
1976	29.20834922993514
1977	31.607611415088584
1978	32.247944782116
1979	37.753119429590015
1980	44.86913480371285
1981	46.048548202686234
1982	51.84450723825098
1983	56.952036167556656
1984	57.28289223579102
1985	60.87653192027891
1986	64.24412829567522
1987	64.9767273749523
1988	65.90469699095884
1989	67.63433085329649
1990	67.02572256775392
1991	61.276172314690534
1992	64.28707813581268
1993	61.665056633071416
1994	60.5461248857036
1995	63.88116029497746
1996	66.59034493511959
1997	71.22932372522621
1998	74.04359862043587
1999	78.32291443798262
2000	82.84559639879691
2001	85.99814352729814
2002	90.88118735378386
2003	81.35629102383496
2004	89.50514979202332
2005	93.43766706304531
2006	100.70245853144114
2007	86.92898730702893
2008	91.42839947327612
2009	83.50580681876973
2010	80.61950372506112
2011	71.03448282708324
2012	69.68179690339868
2013	73.45936696560922
2014	75.81440541659997
2015	70.10831788252113
2016	66.01698515775455
2017	73.89124869344015
2018	75.58513110836492
2019	76.83727733875625
2020	76.6865930829152
2021	77.55564153162526
