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	90.70338101482099
2003	81.18927561487273
2004	89.34238717840573
2005	93.28205257564005
2006	100.55065305209573
2007	86.7686680977608
2008	91.31054796242378
2009	83.38768725767112
2010	80.55670858822677
2011	70.94965637446076
2012	69.56935376182331
2013	73.33895476017652
2014	75.69350004460854
2015	69.97403336070334
2016	65.81667618629739
2017	73.69753384895189
2018	75.41874287701306
2019	76.63369671911596
2020	76.44242509223052
2021	77.30642610539114