Year	kilograms per hectare of arable land
1961	7.571075401730532
1962	8.73015873015873
1963	8.548387096774194
1964	8.561643835616438
1965	6.295985813316137
1966	8.246262658736537
1967	8.17806697349627
1968	10.892199263174756
1969	11.230547088079577
1970	17.765685019206146
1971	28.0564263322884
1972	33.02611367127496
1973	28.86977886977887
1974	26.130806845965772
1975	17.969320672023375
1976	23.406655386350817
1977	20.42540556199305
1978	25.84257109692397
1979	24.810400233713118
1980	34.28363636363636
1981	24.12490922294844
1982	19.087196628397034
1983	23.498179611650485
1984	29.49168474331164
1985	40.612445730824895
1986	38.992392708482846
1987	34.120809166784554
1988	20.63089705675257
1989	16.411838967597138
1990	17.93531987007485
1991	12.603305785123966
1992	12.800846336947897
1993	17.376875082968272
1994	15.955597164638224
1995	6.171033382098683
1996	5.052519611753756
1997	12.679738562091503
1998	14.09737632162903
1999	12.12042225987228
2000	12.046463064474027
2001	13.886324673612027
2002	9.641579435537299
2003	6.001172754774311
2004	25.09515547844655
2005	7.429902809213154
2006	13.26265060240964
2007	14.96157450796626
2008	8.576712511683803
2009	14.279994661684238
2010	15.795787789922688
2011	15.76912823247134
2012	21.328182242056883
2013	22.451375363517517
2014	25.504056550726965
2015	23.532249634821298
2016	21.028605386132195
2017	20.841121704239963
2018	20.758052617890407
2019	20.67564337502988
2020	20.67564337502988
2021	20.67564337502988
