Quarter	Billions of US Dollars
1966-01-01	0.08
1966-04-01	0.05
1966-07-01	0.03
1966-10-01	0.02
1967-01-01	0.04
1967-04-01	0.13
1967-07-01	0.02
1967-10-01	0.02
1968-01-01	0.30
1968-04-01	0.49
1968-07-01	0.21
1968-10-01	0.09
1969-01-01	0.23
1969-04-01	0.03
1969-07-01	0.03
1969-10-01	0.16
1970-01-01	0.07
1970-04-01	0.02
1970-07-01	0.28
1970-10-01	0.04
1971-01-01	0.99
1971-04-01	0.51
1971-07-01	0.28
1971-10-01	1.31
1972-01-01	2.67
1972-04-01	2.58
1972-07-01	2.30
1972-10-01	2.98
1973-01-01	2.47
1973-04-01	2.18
1973-07-01	1.74
1973-10-01	2.27
1974-01-01	1.63
1974-04-01	2.28
1974-07-01	2.02
1974-10-01	3.27
1975-01-01	4.64
1975-04-01	6.45
1975-07-01	3.50
1975-10-01	6.77
1976-01-01	9.56
1976-04-01	7.49
1976-07-01	7.85
1976-10-01	9.10
1977-01-01	8.40
1977-04-01	8.73
1977-07-01	8.69
1977-10-01	8.68
1978-01-01	9.89
1978-04-01	9.27
1978-07-01	9.16
1978-10-01	7.28
1979-01-01	10.35
1979-04-01	9.52
1979-07-01	9.77
1979-10-01	8.28
1980-01-01	6.62
1980-04-01	12.18
1980-07-01	8.83
1980-10-01	9.16
1981-01-01	9.01
1981-04-01	11.63
1981-07-01	10.87
1981-10-01	16.90
1982-01-01	21.79
1982-04-01	17.70
1982-07-01	18.36
1982-10-01	17.39
1983-01-01	20.87
1983-04-01	19.09
1983-07-01	13.69
1983-10-01	20.24
1984-01-01	27.59
1984-04-01	20.79
1984-07-01	23.52
1984-10-01	34.13
1985-01-01	36.25
1985-04-01	36.18
1985-07-01	34.32
1985-10-01	41.04
1986-01-01	50.00
1986-04-01	52.44
1986-07-01	52.09
1986-10-01	46.63
1987-01-01	54.20
1987-04-01	43.90
1987-07-01	39.76
1987-10-01	26.18
1988-01-01	54.48
1988-04-01	56.59
1988-07-01	53.70
1988-10-01	42.94
1989-01-01	73.22
1989-04-01	64.91
1989-07-01	53.39
1989-10-01	57.37
1990-01-01	96.12
1990-04-01	52.14
1990-07-01	59.84
1990-10-01	74.78
1991-01-01	90.50
1991-04-01	78.88
1991-07-01	73.23
1991-10-01	64.68
1992-01-01	97.30
1992-04-01	94.66
1992-07-01	70.50
1992-10-01	80.03
1993-01-01	132.54
1993-04-01	94.60
1993-07-01	116.86
1993-10-01	130.89
1994-01-01	132.46
1994-04-01	144.22
1994-07-01	121.35
1994-10-01	114.79
1995-01-01	115.53
1995-04-01	122.56
1995-07-01	139.62
1995-10-01	125.91
1996-01-01	200.29
1996-04-01	237.70
1996-07-01	246.22
1996-10-01	215.84
1997-01-01	242.55
1997-04-01	222.92
1997-07-01	233.65
1997-10-01	161.89
1998-01-01	277.32
1998-04-01	260.11
1998-07-01	197.17
1998-10-01	203.46
1999-01-01	336.77
1999-04-01	342.57
1999-07-01	317.81
1999-10-01	257.18
2000-01-01	369.17
2000-04-01	349.63
2000-07-01	368.63
2000-10-01	334.44
2001-01-01	554.58
2001-04-01	553.47
2001-07-01	351.43
2001-10-01	467.00
2002-01-01	477.62
2002-04-01	452.70
2002-07-01	327.98
2002-10-01	394.55
2003-01-01	601.21
2003-04-01	620.36
2003-07-01	524.51
2003-10-01	580.19
2004-01-01	758.76
2004-04-01	628.47
2004-07-01	596.46
2004-10-01	661.59
2005-01-01	802.79
2005-04-01	769.98
2005-07-01	639.70
2005-10-01	829.92
2006-01-01	926.95
2006-04-01	935.06
2006-07-01	881.54
2006-10-01	1192.08
2007-01-01	1253.52
2007-04-01	1331.93
2007-07-01	759.35
2007-10-01	779.62
2008-01-01	820.20
2008-04-01	1375.46
2008-07-01	829.35
2008-10-01	1041.44
2009-01-01	1081.25
2009-04-01	1182.61
2009-07-01	868.66
2009-10-01	827.88
2010-01-01	1009.62
2010-04-01	705.86
2010-07-01	858.12
2010-10-01	718.97
2011-01-01	1058.99
2011-04-01	932.99
2011-07-01	638.99
2011-10-01	710.94
2012-01-01	1321.52
2012-04-01	751.68
2012-07-01	847.86
2012-10-01	816.34
2013-01-01	921.01
2013-04-01	894.55
2013-07-01	803.33
2013-10-01	918.49
2014-01-01	1063.45
2014-04-01	1185.01
2014-07-01	891.61
2014-10-01	764.19
2015-01-01	1026.48
2015-04-01	868.73