Year	kilograms per hectare of arable land
1961	0.89100668200241
1962	0.8186979785969084
1963	1.0390529893553822
1964	1.0769451049133099
1965	1.265548712109449
1966	1.5349217531323907
1967	1.9043877210543878
1968	1.9586100080736848
1969	2.161689748422519
1970	2.5961123639572508
1971	3.0241729451776154
1972	3.3330931699142696
1973	3.3651533071049857
1974	3.9148622166307794
1975	4.170124979010243
1976	4.7202758554402156
1977	4.98397140587768
1978	4.564949621274688
1979	5.418353654496057
1980	6.324551224640785
1981	6.7746430575472285
1982	6.672006394884093
1983	6.9866965925321365
1984	7.9550990394779175
1985	7.968534596158905
1986	7.7773175217956965
1987	8.001371333174339
1988	8.767848305103525
1989	8.570810024038284
1990	8.558845348228312
1991	8.27953062194753
1992	8.991450630400907
1993	9.831382428048865
1994	9.05485786956082
1995	7.473867571394524
1996	8.098272236950361
1997	8.384744884744885
1998	7.8497919448297315
1999	8.015237619833865
2000	7.802715367826422
2001	9.815284593543623
2002	10.539321837357134
2003	7.1663777662658354
2004	7.174458208425868
2005	8.028094560525036
2006	8.82286457216873
2007	7.248358460166637
2008	8.280090168595741
2009	8.152480941819151
2010	10.249587055458166
2011	9.236930055630168
2012	9.330391133460683
2013	10.565184563651574
2014	10.386367809335791
2015	10.345147296199915
2016	12.685320874554677
2017	15.734317172786074
2018	15.03616112575815
2019	15.548312246662835
2020	17.648100090886427
2021	15.858787574026989