Year	current US$
1981	298549874.0109422
1982	297926370.2738834
1983	287221944.80126876
1984	289503792.4240736
1985	323197571.82643676
1986	488371141.9403278
1990	237767400.8683671
1998	1024379737.2336583
1999	1019612276.7123866
2000	916706636.6757827
2001	933001045.4766546
2002	1062164715.8672261
2003	1336594832.1958413
2004	1510683508.2782538
2005	1594528707.9828517
2006	1739568055.3274639
2007	2022120900.1435208
2008	2267036261.894471
2009	2275392705.4911695
2010	2230822858.9358687
2011	2411350522.3962913
2012	2279608775.633002
2013	2452470317.2405105
2014	2491763507.0718865
2015	2082689582.3513777
2016	2134521809.8269408
2017	2157184135.0679946