Quarter	Billions of US Dollars
1987-01-01	0.03200
1987-04-01	0.06000
1987-07-01	0.13200
1987-10-01	0.13000
1988-01-01	0.13000
1988-04-01	0.13000
1988-07-01	0.19200
1988-10-01	0.18900
1989-01-01	0.14900
1989-04-01	0.12100
1989-07-01	0.01000
1989-10-01	0.06000
1990-01-01	0.25000
1990-04-01	0.44700
1990-07-01	0.78200
1990-10-01	0.66600
1991-01-01	0.31000
1991-04-01	0.44600
1991-07-01	0.46700
1991-10-01	0.43200
1992-01-01	0.87700
1992-04-01	0.89400
1992-07-01	0.92900
1992-10-01	0.79600
1993-01-01	0.61100
1993-04-01	1.29300
1993-07-01	0.33770
1993-10-01	0.43580
1994-01-01	0.55435
1994-04-01	0.44010
1994-07-01	0.34063
1994-10-01	0.37855
1995-01-01	0.22839
1995-04-01	0.24217
1995-07-01	0.33149
1995-10-01	0.29987
1996-01-01	0.37250
1996-04-01	0.34241
1996-07-01	0.31710
1996-10-01	0.26510
1997-01-01	0.27850
1997-04-01	0.25660
1997-07-01	0.35320
1997-10-01	0.20025
1998-01-01	0.29158
1998-04-01	0.49430
1998-07-01	0.45629
1998-10-01	0.48212
1999-01-01	0.47360
1999-04-01	0.69469
1999-07-01	0.83704
1999-10-01	0.56820
2000-01-01	0.55189
2000-04-01	0.53024
2000-07-01	0.52642
2000-10-01	0.51294
2001-01-01	0.51762
2001-04-01	0.48390
2001-07-01	0.41552
2001-10-01	0.42627
2002-01-01	0.41146
2002-04-01	0.42894
2002-07-01	0.38277
2002-10-01	0.29442
2003-01-01	0.25101
2003-04-01	0.22870
2003-07-01	0.23038
2003-10-01	0.23471
2004-01-01	0.23211
2004-04-01	0.23138
2004-07-01	0.23391
2004-10-01	0.24538
2005-01-01	0.23222
2005-04-01	0.22688
2005-07-01	0.22999
2005-10-01	0.21878
2006-01-01	0.22030
2006-04-01	0.21831
2006-07-01	0.21804
2006-10-01	0.09456
2007-01-01	0.09529
2007-04-01	0.09622
2007-07-01	0.09954
2007-10-01	0.10222
2008-01-01	0.10760
2008-04-01	0.10737
2008-07-01	0.10016
2008-10-01	0.09825
2009-01-01	0.09524
2009-04-01	0.09932
2009-07-01	0.10183
2009-10-01	0.10066
2010-01-01	0.09609
2010-04-01	0.09012
2010-07-01	0.09692
2010-10-01	0.09551
2011-01-01	0.09968
2011-04-01	0.10090
2011-07-01	0.09621
2011-10-01	0.09342
2012-01-01	0.09548
2012-04-01	0.09170
2012-07-01	0.09337
2012-10-01	0.09468
2013-01-01	0.09276
2013-04-01	0.09412
2013-07-01	0.09622
2013-10-01	0.09763
2014-01-01	0.09761
2014-04-01	0.09697
2014-07-01	0.09166
2014-10-01	0.08948
2015-01-01	0.08266
2015-04-01	0.07228