Year	US Dollars, Monthly Level
1990-01-01	25675326000
1991-01-01	29142381000
1992-01-01	33967008000
1993-01-01	36822798000
1994-01-01	40053422000
1995-01-01	45418216000
1996-01-01	49814754484
1997-01-01	53443602252
1998-01-01	48847638595
1999-01-01	48665452518
2000-01-01	62124016182
2001-01-01	56321104904
2002-01-01	57159271616
2003-01-01	61058246995
2004-01-01	71584608796
2005-01-01	85659952615
2006-01-01	100798624280
2007-01-01	114100890751
2008-01-01	137020424402
2009-01-01	116511264847
2010-01-01	157779103470
2011-01-01	203496620000
2012-01-01	190026944880
2013-01-01	182551798697
2014-01-01	175980836906
2015-01-01	150366291503
2016-01-01	145186211247
2017-01-01	168828175938