Year	kilograms per hectare of arable land
1964	2.238233665559247
1965	2.684162010495589
1966	2.9821013500293483
1967	3.6296437224327516
1968	3.928485044562044
1969	4.073023416241904
1970	4.532369372329938
1971	5.034343047524222
1972	5.715079383174871
1973	6.0265761558729505
1974	5.9240559259794265
1975	6.944784205414592
1976	7.719152710837305
1977	8.8857521236702
1978	9.023154531163405
1979	10.292949300210202
1980	10.701283974667561
1981	11.223487227727784
1982	12.100596395123835
1983	13.167415298597584
1984	13.816604415166656
1985	13.580868524810931
1986	14.118469411312223
1987	14.390898727235996
1988	14.991393889976477
1989	15.337665558845128
1990	15.359691606374106
1991	16.07585621466172
1992	17.3945008174929
1993	16.677423861982337
1994	18.50954678902128
1995	20.151412136529444
1996	19.72864809950521
1997	20.375945128012752
1998	19.335967470759318
1999	21.142089241049266
2000	20.672383731250182
2001	19.93334649167556
2002	21.506536450868285
2003	18.143571632431975
2004	20.197804961985227
2005	20.039809055370238
2006	20.6276512692126
2007	20.514003057351783
2008	21.330898750900687
2009	20.001049252697246
2010	21.64437962686442
2011	24.367844102113526
2012	24.628455441517374
2013	22.960263916971897
2014	26.08526219437588
2015	26.281844886833962
2016	27.401040060557026
2017	30.05312637967163
2018	30.699624635813876
2019	33.49386497523061
2020	37.80089853396709
2021	35.83103791439381