Year	kilograms per hectare of arable land
1961	2.588235294117647
1962	2.3391812865497075
1963	2.1994152046783624
1964	2.211078717201166
1965	2.6623906705539357
1966	3.941860465116279
1967	5.300581395348837
1968	5.966956521739131
1969	4.998260869565217
1970	7.223188405797101
1971	10.115606936416185
1972	9.595375722543352
1973	8.184438040345821
1974	12.622478386167147
1975	20.632183908045977
1976	24.942528735632184
1977	29.340974212034386
1978	21.085714285714285
1979	34.36571428571428
1980	30.318311466058187
1981	42.281001137656425
1982	49.110481586402265
1983	51.415211267605635
1984	44.89550561797753
1985	37.884722999440406
1986	43.883008356545965
1987	56.71666666666667
1988	48.833333333333336
1989	43.65650969529086
1990	42.99168975069252
1991	46.850828729281766
1992	47.43801652892562
1993	61.10192837465565
1994	40.821917808219176
1995	47.593582887700535
1996	30.76923076923077
1997	30.42406311637081
1998	27.823691460055098
1999	47.65840220385675
2000	30.303030303030305
2001	40.33057851239669
2002	35.99719008264463
2003	19.547101928374655
2004	28.827085714285715
2005	29.980302857142856
2006	31.463554285714284
2007	30.443548571428575
2008	29.42041714285714
2009	33.48867428571429
2010	38.555885780885774
2011	47.16692890442891
2012	47.973837209302324
2013	36.208058139534884
2014	22.917052325581395
2015	15.672953488372093
2016	15.640831395348835
2017	26.05164534883721
2018	16.415674418604652
2019	18.10996511627907
2020	18.483145348837212
2021	14.723848837209303