Year	US Dollars, Monthly Level
1990-01-01	12790000000.000000
1991-01-01	14637586226.914999
1992-01-01	13341499649.132800
1993-01-01	14215944841.296500
1994-01-01	17166064305.557100
1995-01-01	23049482388.909400
1996-01-01	24557089806.676502
1997-01-01	25868299705.904100
1998-01-01	28438700785.133800
1999-01-01	27518931154.681000
2000-01-01	31995411510.650200
2001-01-01	36361858550.037100
2002-01-01	41256195258.804504
2003-01-01	54105290783.675600
2004-01-01	75273389677.419400
2005-01-01	90175576663.039000
2006-01-01	112001140168.350000
2007-01-01	141748078696.216000
2008-01-01	171696770276.324000
2009-01-01	137570900336.764980
2010-01-01	159657861546.684000
2011-01-01	189176936766.776000
2012-01-01	185687252637.661000
2013-01-01	204936315494.902000
2014-01-01	219873825244.958980
2015-01-01	198740902345.949000
2016-01-01	204062480552.968000
2017-01-01	234459927441.400000