Quarter	Billions of US Dollars
1973-07-01	0.026
1973-10-01	0.031
1974-01-01	0.033
1974-04-01	0.033
1974-07-01	0.034
1974-10-01	0.039
1975-01-01	0.064
1975-04-01	0.064
1975-07-01	0.060
1975-10-01	0.062
1976-01-01	0.064
1976-04-01	0.065
1976-07-01	0.065
1976-10-01	0.067
1977-01-01	0.065
1977-04-01	0.109
1977-07-01	0.135
1977-10-01	0.141
1978-01-01	0.144
1978-04-01	0.144
1978-07-01	0.102
1978-10-01	0.087
1979-01-01	0.084
1979-04-01	0.082
1979-07-01	0.084
1979-10-01	0.085
1980-01-01	0.083
1980-04-01	0.085
1980-07-01	0.084
1980-10-01	0.082
1981-01-01	0.099
1981-04-01	0.096
1981-07-01	0.148
1981-10-01	0.184
1982-01-01	0.182
1982-04-01	0.181
1982-07-01	0.250
1982-10-01	0.330
1983-01-01	0.428
1983-04-01	0.721
1983-07-01	0.831
1983-10-01	1.181
1984-01-01	1.574
1984-04-01	2.265
1984-07-01	2.393
1984-10-01	2.664
1985-01-01	3.178
1985-04-01	3.663
1985-07-01	4.644
1985-10-01	5.263
1986-01-01	5.426
1986-04-01	5.849
1986-07-01	6.362
1986-10-01	6.677
1987-01-01	6.962
1987-04-01	7.016
1987-07-01	6.836
1987-10-01	7.006
1988-01-01	7.122
1988-04-01	6.977
1988-07-01	7.068
1988-10-01	7.167
1989-01-01	7.666
1989-04-01	7.724
1989-07-01	7.774
1989-10-01	7.631
1990-01-01	7.848
1990-04-01	7.446
1990-07-01	8.126
1990-10-01	7.946
1991-01-01	8.383
1991-04-01	8.253
1991-07-01	8.354
1991-10-01	8.334
1992-01-01	7.337
1992-04-01	7.269
1992-07-01	7.136
1992-10-01	6.900
1993-01-01	6.892
1993-04-01	7.071
1993-07-01	8.487
1993-10-01	10.042
1994-01-01	10.990
1994-04-01	11.650
1994-07-01	12.807
1994-10-01	15.263
1995-01-01	15.261
1995-04-01	15.783
1995-07-01	15.547
1995-10-01	17.404
1996-01-01	16.196
1996-04-01	14.860
1996-07-01	16.091
1996-10-01	17.423
1997-01-01	18.303
1997-04-01	20.341
1997-07-01	21.157
1997-10-01	20.653
1998-01-01	20.348
1998-04-01	20.467
1998-07-01	20.541
1998-10-01	20.412
1999-01-01	21.185
1999-04-01	22.166
1999-07-01	23.072
1999-10-01	23.842
2000-01-01	24.329
2000-04-01	23.459
2000-07-01	23.922
2000-10-01	25.560
2001-01-01	25.237
2001-04-01	27.663
2001-07-01	27.467
2001-10-01	26.545
2002-01-01	30.032
2002-04-01	32.747
2002-07-01	33.758
2002-10-01	34.929
2003-01-01	35.962
2003-04-01	38.271
2003-07-01	38.843
2003-10-01	39.091
2004-01-01	40.098
2004-04-01	40.627
2004-07-01	42.098
2004-10-01	43.051
2005-01-01	44.310
2005-04-01	44.228
2005-07-01	44.510
2005-10-01	40.397
2006-01-01	40.454
2006-04-01	41.514
2006-07-01	40.743
2006-10-01	42.263
2007-01-01	41.977
2007-04-01	44.064
2007-07-01	44.529
2007-10-01	44.203
2008-01-01	44.165
2008-04-01	44.112
2008-07-01	45.324
2008-10-01	45.770
2009-01-01	42.450
2009-04-01	44.374
2009-07-01	45.506
2009-10-01	45.882
2010-01-01	47.417
2010-04-01	49.477
2010-07-01	53.237
2010-10-01	57.781
2011-01-01	57.722
2011-04-01	69.232
2011-07-01	72.569
2011-10-01	76.501
2012-01-01	84.843
2012-04-01	89.280
2012-07-01	94.658
2012-10-01	99.445
2013-01-01	104.636
2013-04-01	114.318
2013-07-01	116.695
2013-10-01	120.530
2014-01-01	127.207
2014-04-01	136.344
2014-07-01	146.110
2014-10-01	147.776
2015-01-01	151.527
2015-04-01	160.743