Quarter	Billions of US Dollars
1972-07-01	0.031
1972-10-01	0.091
1973-01-01	0.095
1973-04-01	0.126
1973-07-01	0.126
1973-10-01	0.158
1974-01-01	0.161
1974-04-01	0.159
1974-07-01	0.156
1974-10-01	0.185
1975-01-01	0.222
1975-04-01	0.221
1975-07-01	0.216
1975-10-01	0.216
1976-01-01	0.218
1976-04-01	0.267
1976-07-01	0.312
1976-10-01	0.505
1977-01-01	0.591
1977-04-01	0.798
1977-07-01	1.041
1977-10-01	1.568
1978-01-01	1.860
1978-04-01	2.046
1978-07-01	2.418
1978-10-01	2.641
1979-01-01	2.765
1979-04-01	2.808
1979-07-01	3.130
1979-10-01	3.284
1980-01-01	3.014
1980-04-01	3.557
1980-07-01	3.580
1980-10-01	3.476
1981-01-01	3.313
1981-04-01	3.054
1981-07-01	3.131
1981-10-01	3.207
1982-01-01	2.993
1982-04-01	2.840
1982-07-01	2.701
1982-10-01	2.931
1983-01-01	2.874
1983-04-01	2.789
1983-07-01	2.758
1983-10-01	2.658
1984-01-01	2.747
1984-04-01	2.494
1984-07-01	2.318
1984-10-01	2.117
1985-01-01	2.226
1985-04-01	2.316
1985-07-01	2.677
1985-10-01	2.339
1986-01-01	2.602
1986-04-01	2.728
1986-07-01	2.895
1986-10-01	2.761
1987-01-01	2.817
1987-04-01	2.769
1987-07-01	2.507
1987-10-01	2.572
1988-01-01	2.511
1988-04-01	1.940
1988-07-01	1.592
1988-10-01	1.584
1989-01-01	1.304
1989-04-01	1.194
1989-07-01	2.106
1989-10-01	1.925
1990-01-01	1.834
1990-04-01	1.837
1990-07-01	1.882
1990-10-01	1.897
1991-01-01	1.837
1991-04-01	1.744
1991-07-01	2.314
1991-10-01	3.209
1992-01-01	3.667
1992-04-01	5.472
1992-07-01	5.663
1992-10-01	5.651
1993-01-01	5.832
1993-04-01	7.269
1993-07-01	8.381
1993-10-01	10.164
1994-01-01	10.985
1994-04-01	53.696
1994-07-01	53.851
1994-10-01	54.705
1995-01-01	54.776
1995-04-01	55.731
1995-07-01	56.579
1995-10-01	57.171
1996-01-01	58.380
1996-04-01	62.331
1996-07-01	62.197
1996-10-01	65.536
1997-01-01	66.043
1997-04-01	71.666
1997-07-01	74.782
1997-10-01	74.266
1998-01-01	75.995
1998-04-01	79.358
1998-07-01	80.140
1998-10-01	70.658
1999-01-01	69.013
1999-04-01	70.793
1999-07-01	72.650
1999-10-01	76.629
2000-01-01	80.681
2000-04-01	76.780
2000-07-01	83.172
2000-10-01	84.164
2001-01-01	85.784
2001-04-01	81.182
2001-07-01	82.133
2001-10-01	80.686
2002-01-01	83.737
2002-04-01	87.837
2002-07-01	88.943
2002-10-01	88.219
2003-01-01	88.369
2003-04-01	93.132
2003-07-01	96.408
2003-10-01	102.278
2004-01-01	105.085
2004-04-01	102.207
2004-07-01	104.430
2004-10-01	105.211
2005-01-01	106.471
2005-04-01	105.118
2005-07-01	106.166
2005-10-01	107.663
2006-01-01	111.223
2006-04-01	100.892
2006-07-01	103.727
2006-10-01	110.673
2007-01-01	112.798
2007-04-01	117.555
2007-07-01	116.142
2007-10-01	117.441
2008-01-01	121.233
2008-04-01	123.063
2008-07-01	117.574
2008-10-01	114.883
2009-01-01	114.732
2009-04-01	118.657
2009-07-01	127.484
2009-10-01	139.241
2010-01-01	146.347
2010-04-01	152.279
2010-07-01	166.278
2010-10-01	172.377
2011-01-01	183.663
2011-04-01	197.189
2011-07-01	195.845
2011-10-01	203.660
2012-01-01	226.934
2012-04-01	230.075
2012-07-01	238.963
2012-10-01	251.976
2013-01-01	257.173
2013-04-01	274.222
2013-07-01	279.190
2013-10-01	284.507
2014-01-01	301.105
2014-04-01	314.724
2014-07-01	323.703
2014-10-01	316.729
2015-01-01	300.299
2015-04-01	304.490