Quarter	Billions of US Dollars
1968-07-01	0.04
1968-10-01	0.04
1969-01-01	0.14
1969-04-01	0.15
1969-07-01	0.17
1969-10-01	0.17
1970-01-01	0.17
1970-04-01	0.17
1970-07-01	0.17
1970-10-01	0.17
1971-01-01	0.17
1971-04-01	0.17
1971-07-01	0.17
1971-10-01	0.19
1972-01-01	0.21
1972-04-01	0.30
1972-07-01	0.53
1972-10-01	0.60
1973-01-01	0.82
1973-04-01	0.98
1973-07-01	1.04
1973-10-01	1.04
1974-01-01	1.10
1974-04-01	1.20
1974-07-01	1.37
1974-10-01	1.76
1975-01-01	2.02
1975-04-01	2.26
1975-07-01	2.24
1975-10-01	2.36
1976-01-01	2.45
1976-04-01	2.83
1976-07-01	3.10
1976-10-01	3.27
1977-01-01	3.49
1977-04-01	3.74
1977-07-01	4.15
1977-10-01	4.50
1978-01-01	4.78
1978-04-01	4.93
1978-07-01	5.61
1978-10-01	5.83
1979-01-01	6.49
1979-04-01	6.77
1979-07-01	6.83
1979-10-01	6.77
1980-01-01	6.43
1980-04-01	7.67
1980-07-01	8.31
1980-10-01	8.91
1981-01-01	8.89
1981-04-01	8.80
1981-07-01	9.23
1981-10-01	10.43
1982-01-01	10.17
1982-04-01	10.36
1982-07-01	10.47
1982-10-01	12.38
1983-01-01	13.68
1983-04-01	14.65
1983-07-01	15.06
1983-10-01	17.01
1984-01-01	19.71
1984-04-01	20.77
1984-07-01	21.89
1984-10-01	22.93
1985-01-01	23.96
1985-04-01	25.14
1985-07-01	26.70
1985-10-01	26.94
1986-01-01	28.67
1986-04-01	31.15
1986-07-01	34.03
1986-10-01	36.04
1987-01-01	40.36
1987-04-01	42.77
1987-07-01	43.66
1987-10-01	47.10
1988-01-01	48.03
1988-04-01	49.07
1988-07-01	50.23
1988-10-01	56.12
1989-01-01	55.16
1989-04-01	57.80
1989-07-01	60.98
1989-10-01	66.14
1990-01-01	71.15
1990-04-01	73.48
1990-07-01	79.13
1990-10-01	83.07
1991-01-01	80.83
1991-04-01	79.81
1991-07-01	87.12
1991-10-01	95.06
1992-01-01	94.05
1992-04-01	101.04
1992-07-01	109.28
1992-10-01	103.39
1993-01-01	107.82
1993-04-01	112.72
1993-07-01	112.24
1993-10-01	113.86
1994-01-01	122.72
1994-04-01	129.70
1994-07-01	139.58
1994-10-01	145.06
1995-01-01	163.04
1995-04-01	172.53
1995-07-01	173.07
1995-10-01	178.34
1996-01-01	187.07
1996-04-01	193.30
1996-07-01	199.90
1996-10-01	204.00
1997-01-01	205.00
1997-04-01	209.55
1997-07-01	218.12
1997-10-01	221.74
1998-01-01	231.14
1998-04-01	248.65
1998-07-01	275.16
1998-10-01	282.76
1999-01-01	287.05
1999-04-01	318.42
1999-07-01	355.93
1999-10-01	357.70
2000-01-01	358.05
2000-04-01	372.69
2000-07-01	383.46
2000-10-01	423.24
2001-01-01	428.33
2001-04-01	440.16
2001-07-01	479.86
2001-10-01	492.72
2002-01-01	509.89
2002-04-01	585.04
2002-07-01	603.13
2002-10-01	646.21
2003-01-01	688.44
2003-04-01	751.67
2003-07-01	780.36
2003-10-01	870.16
2004-01-01	853.11
2004-04-01	864.86
2004-07-01	881.99
2004-10-01	980.92
2005-01-01	963.07
2005-04-01	932.06
2005-07-01	936.38
2005-10-01	961.20
2006-01-01	1008.03
2006-04-01	1097.90
2006-07-01	1133.63
2006-10-01	1236.37
2007-01-01	1308.77
2007-04-01	1375.06
2007-07-01	1442.42
2007-10-01	1510.80
2008-01-01	1604.71
2008-04-01	1671.83
2008-07-01	1545.13
2008-10-01	1524.27
2009-01-01	1552.26
2009-04-01	1714.72
2009-07-01	1784.02
2009-10-01	1783.18
2010-01-01	1751.20
2010-04-01	1616.59
2010-07-01	1813.90
2010-10-01	1802.92
2011-01-01	1903.69
2011-04-01	1954.97
2011-07-01	1860.07
2011-10-01	1844.97
2012-01-01	1924.30
2012-04-01	1840.43
2012-07-01	1923.49
2012-10-01	1967.40
2013-01-01	1921.51
2013-04-01	1973.11
2013-07-01	2053.08
2013-10-01	2083.20
2014-01-01	2088.22
2014-04-01	2075.82
2014-07-01	1948.18
2014-10-01	1895.66
2015-01-01	1737.69
2015-04-01	1814.12