Quarter	Billions of US Dollars
1966-01-01	0.07
1966-04-01	0.03
1966-07-01	0.02
1967-01-01	0.01
1967-04-01	0.11
1967-10-01	0.02
1968-01-01	0.19
1968-04-01	0.35
1968-07-01	0.14
1968-10-01	0.06
1969-01-01	0.14
1969-04-01	0.03
1969-07-01	0.03
1969-10-01	0.15
1970-01-01	0.03
1970-07-01	0.08
1970-10-01	0.02
1971-01-01	0.59
1971-04-01	0.20
1971-07-01	0.13
1971-10-01	0.43
1972-01-01	1.19
1972-04-01	1.65
1972-07-01	1.43
1972-10-01	1.89
1973-01-01	1.53
1973-04-01	1.13
1973-07-01	1.08
1973-10-01	1.26
1974-01-01	1.04
1974-04-01	1.22
1974-07-01	1.59
1974-10-01	1.90
1975-01-01	3.54
1975-04-01	4.47
1975-07-01	2.76
1975-10-01	4.54
1976-01-01	6.86
1976-04-01	5.38
1976-07-01	4.45
1976-10-01	6.18
1977-01-01	5.23
1977-04-01	5.78
1977-07-01	4.75
1977-10-01	5.40
1978-01-01	6.40
1978-04-01	6.83
1978-07-01	4.39
1978-10-01	4.29
1979-01-01	7.50
1979-04-01	5.88
1979-07-01	5.83
1979-10-01	5.26
1980-01-01	5.15
1980-04-01	7.29
1980-07-01	5.12
1980-10-01	5.87
1981-01-01	5.95
1981-04-01	7.52
1981-07-01	7.06
1981-10-01	10.86
1982-01-01	13.54
1982-04-01	9.90
1982-07-01	10.34
1982-10-01	10.69
1983-01-01	14.00
1983-04-01	11.34
1983-07-01	7.60
1983-10-01	13.20
1984-01-01	18.84
1984-04-01	14.50
1984-07-01	17.60
1984-10-01	25.54
1985-01-01	28.40
1985-04-01	27.99
1985-07-01	25.55
1985-10-01	31.70
1986-01-01	39.47
1986-04-01	43.41
1986-07-01	43.96
1986-10-01	37.87
1987-01-01	43.00
1987-04-01	35.86
1987-07-01	31.71
1987-10-01	19.21
1988-01-01	43.54
1988-04-01	47.39
1988-07-01	45.63
1988-10-01	33.18
1989-01-01	58.37
1989-04-01	56.82
1989-07-01	41.14
1989-10-01	48.15
1990-01-01	48.14
1990-04-01	37.97
1990-07-01	44.00
1990-10-01	46.15
1991-01-01	66.04
1991-04-01	65.74
1991-07-01	56.80
1991-10-01	49.55
1992-01-01	68.60
1992-04-01	61.44
1992-07-01	50.52
1992-10-01	58.27
1993-01-01	99.28
1993-04-01	71.31
1993-07-01	92.25
1993-10-01	80.15
1994-01-01	102.35
1994-04-01	80.23
1994-07-01	88.98
1994-10-01	78.62
1995-01-01	84.69
1995-04-01	90.05
1995-07-01	97.03
1995-10-01	93.27
1996-01-01	142.06
1996-04-01	176.23
1996-07-01	177.67
1996-10-01	139.50
1997-01-01	160.64
1997-04-01	145.09
1997-07-01	150.11
1997-10-01	106.08
1998-01-01	189.61
1998-04-01	188.61
1998-07-01	141.85
1998-10-01	147.23
1999-01-01	262.10
1999-04-01	273.70
1999-07-01	261.21
1999-10-01	195.18
2000-01-01	259.33
2000-04-01	284.64
2000-07-01	286.06
2000-10-01	279.53
2001-01-01	459.52
2001-04-01	428.91
2001-07-01	287.22
2001-10-01	392.38
2002-01-01	393.41
2002-04-01	370.93
2002-07-01	269.39
2002-10-01	322.75
2003-01-01	501.57
2003-04-01	523.69
2003-07-01	450.99
2003-10-01	506.98
2004-01-01	660.95
2004-04-01	530.08
2004-07-01	507.06
2004-10-01	567.09
2005-01-01	672.87
2005-04-01	659.74
2005-07-01	515.97
2005-10-01	684.43
2006-01-01	767.27
2006-04-01	787.37
2006-07-01	715.33
2006-10-01	959.78
2007-01-01	1015.13
2007-04-01	1069.60
2007-07-01	620.47
2007-10-01	660.93
2008-01-01	706.44
2008-04-01	1233.74
2008-07-01	749.03
2008-10-01	974.01
2009-01-01	962.09
2009-04-01	1005.07
2009-07-01	744.51
2009-10-01	701.15
2010-01-01	842.42
2010-04-01	575.27
2010-07-01	692.13
2010-10-01	591.30
2011-01-01	849.47
2011-04-01	742.92
2011-07-01	493.07
2011-10-01	551.26
2012-01-01	930.89
2012-04-01	565.03
2012-07-01	641.16
2012-10-01	592.77
2013-01-01	672.50
2013-04-01	636.07
2013-07-01	603.89
2013-10-01	702.32
2014-01-01	791.38
2014-04-01	857.46
2014-07-01	667.84
2014-10-01	568.53
2015-01-01	787.60
2015-04-01	642.19