Year	US Dollars, Monthly Level
1990-01-01	21562019917.478000
1991-01-01	26025652072.699800
1992-01-01	27076658180.773200
1993-01-01	28181691839.795400
1994-01-01	32144910724.554700
1995-01-01	40443070012.287300
1996-01-01	43018881589.716300
1997-01-01	40891886006.545810
1998-01-01	27643948145.849500
1999-01-01	24214051766.076200
2000-01-01	33224670692.762500
2001-01-01	31263310278.976800
2002-01-01	30804500105.580100
2003-01-01	33182797445.268795
2004-01-01	46231548925.958595
2005-01-01	57251136909.564100
2006-01-01	60947463088.070700
2007-01-01	74813977595.530000
2008-01-01	124593238848.618990
2009-01-01	98397864826.716800
2010-01-01	135687984513.598980
2011-01-01	176423377362.861000
2012-01-01	191838065798.509000
2013-01-01	186424703022.630000
2014-01-01	176739762895.165000
2015-01-01	143394540523.216000
2016-01-01	135671326431.900010
2017-01-01	157145006645.433000