Year	US Dollars
1990	121643008230.39401
1991	109913462528.91
1992	102141955051.563
1993	105967029541.47198
1994	112614332259.82899
1995	122908406343.88603
1996	129545323074.828
1997	125215117290.716
1998	124039941539.06099
1999	125041728173.689
2000	130976318174.28697
2001	144699977610.00998
2002	154447590788.19199
2003	164909024918.62695
2004	187854049426.42999
2005	201288450133.77499
2006	239568308024.71698
2007	278735971042.40698
2008	334871652182.86493
2009	330712828273.43896
2010	339501335256.336
2011	356578785300.24695
2012	374201136911.67804
2013	388303470710.784
2014	405118821939.66089
2015	417378763099.62909
2016	442188659309.16602
2017	492575315346.28406