Quarter	US Dollars, monthly level
1991-01-01	2338130706.0888996
1991-04-01	2283994688.5372000
1991-07-01	2338076738.3367800
1991-10-01	3234939487.8106403
1992-01-01	2526904257.4829903
1992-04-01	2701769670.9858200
1992-07-01	2735746378.3457900
1992-10-01	2712232121.8178096
1993-01-01	2070416144.6658902
1993-04-01	2197877124.6241000
1993-07-01	2160365775.6103000
1993-10-01	2460120226.8766503
1994-01-01	2263312322.7987404
1994-04-01	2436027361.2552900
1994-07-01	2804775308.2064800
1994-10-01	3190488277.9317300
1995-01-01	2713697131.9048200
1995-04-01	3064367339.5956000
1995-07-01	3338620135.7605900
1995-10-01	3672228202.6678100
1996-01-01	3631271022.3910003
1996-04-01	3829987715.1502200
1996-07-01	3836664432.4774103
1996-10-01	4335753571.8394400
1997-01-01	4080416370.9289103
1997-04-01	4600352294.6949400
1997-07-01	4720526768.9810200
1997-10-01	5599354869.4152000
1998-01-01	5255187707.2446400
1998-04-01	5607067953.2199900
1998-07-01	5645472092.4818500
1998-10-01	6503615290.6982390
1999-01-01	5744675545.6411600
1999-04-01	5824815640.5618990
1999-07-01	6096676274.3124600
1999-10-01	7285976583.8938700
2000-01-01	6471420959.1187600
2000-04-01	6827273657.5236100
2000-07-01	6877797923.0664600
2000-10-01	7818407612.7736600
2001-01-01	7522967938.5376900
2001-04-01	7609654484.5157995
2001-07-01	7325337198.1716190
2001-10-01	8075487787.2562010
2002-01-01	7821555724.4414810
2002-04-01	8733503095.7398510
2002-07-01	8630441760.0513900
2002-10-01	9320685422.7683490
2003-01-01	9520215566.2803900
2003-04-01	10429244567.6751000
2003-07-01	10664383954.6708000
2003-10-01	12449992818.6618000
2004-01-01	12746982602.7526020
2004-04-01	13215547916.4518010
2004-07-01	13254635062.2366000
2004-10-01	15706030547.0587000
2005-01-01	14685602686.9693010
2005-04-01	15802179328.3687000
2005-07-01	15193186733.7411000
2005-10-01	16104268770.9687020
2006-01-01	16250918335.4011000
2006-04-01	18091951712.2254000
2006-07-01	18331228123.2258000
2006-10-01	20824694804.6592000
2007-01-01	21347016232.6459000
2007-04-01	22752724192.2208000
2007-07-01	23584145348.1645000
2007-10-01	26310117312.5573000
2008-01-01	28236275089.9144020
2008-04-01	30157909122.3893970
2008-07-01	27530689286.4418000
2008-10-01	22089920283.8029020
2009-01-01	17862302208.5231000
2009-04-01	19639202614.7981000
2009-07-01	21275227621.9050980
2009-10-01	23998633047.3929980
2010-01-01	22383636937.5712000
2010-04-01	22272632028.9553000
2010-07-01	23470313284.5039000
2010-10-01	26725562882.7649000
2011-01-01	27634659395.3220000
2011-04-01	28475772616.3668020
2011-07-01	27939854129.8903000
2011-10-01	27330878055.6769030
2012-01-01	26188532580.7283970
2012-04-01	25874843316.1201000
2012-07-01	24966491865.6521000
2012-10-01	25983370342.9703000
2013-01-01	25975260643.8723000
2013-04-01	26579411834.7631000
2013-07-01	26849625070.0899000
2013-10-01	28507854107.9114000
2014-01-01	28294348460.0454000
2014-04-01	29010841550.7203000
2014-07-01	28098888569.1005000
2014-10-01	26797473081.9178000
2015-01-01	25073774523.0318000
2015-04-01	25177603728.6865000
2015-07-01	24872203711.9174000
2015-10-01	25211795574.7484000
2016-01-01	24805628853.0783000
2016-04-01	27047059434.4189030
2016-07-01	25490091040.0268020
2016-10-01	25638072900.0325000
2017-01-01	26953827387.4393000
2017-04-01	28266179756.8359000
2017-07-01	28642103209.0833970
2017-10-01	29894399520.4937970
2018-01-01	32143765434.5031000
2018-04-01	32399757409.5071030
2018-07-01	29148239971.9642000