Year	kilograms per hectare of arable land
1978	47.50562324273665
1979	47.58142790480635
1980	48.6570945945946
1987	47.20574733749541
1992	67.98232995019858
1993	51.38067680537989
1997	38.7225137987799
1998	34.75481824835326
1999	33.693143428555985
2000	34.76207409187936
2001	34.34151322862387
2002	39.27641760449615
2003	39.045348437818035
2004	44.01932264104309
2005	40.00892813246674
2006	38.90571761682688
2007	42.29809421747604
2008	42.36169627405446
2009	36.08180815583518
2010	39.84620109831878
2011	38.694203118194565
2012	44.45049043797682
2013	47.222775494915886
2014	47.538263892387526
2015	43.085010279456455
2016	46.22780382863784
2017	48.071352493608856
2018	51.170158185197955
2019	47.05766667579611
2020	42.801415269485666
2021	44.8473928459721