Quarter	Millions of US Dollars
1968-07-01	40
1968-10-01	40
1969-01-01	40
1969-04-01	40
1969-07-01	40
1969-10-01	40
1970-01-01	40
1970-04-01	40
1970-07-01	40
1970-10-01	40
1971-01-01	40
1971-04-01	40
1971-07-01	40
1971-10-01	40
1972-01-01	40
1972-04-01	40
1972-07-01	40
1972-10-01	40
1973-01-01	40
1973-04-01	40
1973-07-01	40
1973-10-01	42
1974-01-01	93
1974-04-01	93
1974-07-01	93
1974-10-01	93
1975-01-01	113
1975-04-01	113
1975-07-01	111
1975-10-01	112
1976-01-01	113
1976-04-01	113
1976-07-01	114
1976-10-01	114
1977-01-01	113
1977-04-01	114
1977-07-01	115
1977-10-01	119
1978-01-01	121
1978-04-01	121
1978-07-01	127
1978-10-01	126
1979-01-01	124
1979-04-01	125
1979-07-01	127
1979-10-01	126
1980-01-01	121
1980-04-01	156
1980-07-01	155
1980-10-01	153
1981-01-01	150
1981-04-01	168
1981-07-01	169
1981-10-01	309
1982-01-01	305
1982-04-01	332
1982-07-01	330
1982-10-01	333
1983-01-01	331
1983-04-01	330
1983-07-01	331
1983-10-01	329
1984-01-01	329
1984-04-01	328
1984-07-01	344
1984-10-01	381
1985-01-01	531
1985-04-01	610
1985-07-01	663
1985-10-01	871
1986-01-01	1220
1986-04-01	1272
1986-07-01	1320
1986-10-01	1360
1987-01-01	2091
1987-04-01	2086
1987-07-01	2091
1987-10-01	2537
1988-01-01	2545
1988-04-01	2546
1988-07-01	2785
1988-10-01	2937
1989-01-01	2830
1989-04-01	3015
1989-07-01	3085
1989-10-01	3388
1990-01-01	3483
1990-04-01	3544
1990-07-01	3843
1990-10-01	4121
1991-01-01	4262
1991-04-01	4211
1991-07-01	4926
1991-10-01	5430
1992-01-01	4742
1992-04-01	5346
1992-07-01	5599
1992-10-01	4933
1993-01-01	4752
1993-04-01	4695
1993-07-01	5573
1993-10-01	5692
1994-01-01	5914
1994-04-01	6266
1994-07-01	6617
1994-10-01	6162
1995-01-01	6494
1995-04-01	6389
1995-07-01	6353
1995-10-01	6317
1996-01-01	6565
1996-04-01	6570
1996-07-01	6905
1996-10-01	7100
1997-01-01	7262
1997-04-01	7740
1997-07-01	8574
1997-10-01	8608
1998-01-01	8926
1998-04-01	9114
1998-07-01	8970
1998-10-01	9065
1999-01-01	9027
1999-04-01	8580
1999-07-01	8514
1999-10-01	8091
2000-01-01	8330
2000-04-01	8176
2000-07-01	7547
2000-10-01	7565
2001-01-01	7322
2001-04-01	7071
2001-07-01	6962
2001-10-01	6945
2002-01-01	7045
2002-04-01	7264
2002-07-01	6882
2002-10-01	6423
2003-01-01	6208
2003-04-01	6258
2003-07-01	6379
2003-10-01	6569
2004-01-01	7369
2004-04-01	7856
2004-07-01	9181
2004-10-01	11257
2005-01-01	13575
2005-04-01	13959
2005-07-01	15134
2005-10-01	16660
2006-01-01	20185
2006-04-01	22545
2006-07-01	23719
2006-10-01	26195
2007-01-01	32551
2007-04-01	36190
2007-07-01	36876
2007-10-01	40281
2008-01-01	40953
2008-04-01	41086
2008-07-01	41990
2008-10-01	42662
2009-01-01	40668
2009-04-01	41427
2009-07-01	41866
2009-10-01	44835
2010-01-01	43747
2010-04-01	43307
2010-07-01	43250
2010-10-01	45858
2011-01-01	47674
2011-04-01	51870
2011-07-01	53201
2011-10-01	50701
2012-01-01	54280
2012-04-01	52523
2012-07-01	53721
2012-10-01	55461
2013-01-01	58308
2013-04-01	66098
2013-07-01	68013
2013-10-01	71676
2014-01-01	74305
2014-04-01	79181
2014-07-01	85195
2014-10-01	85763
2015-01-01	85746
2015-04-01	89667
2015-07-01	88555
2015-10-01	86957
2016-01-01	86100
2016-04-01	84477
2016-07-01	86756
2016-10-01	83917
2017-01-01	90698
2017-04-01	92385
2017-07-01	94690
2017-10-01	100371
2018-01-01	100030
2018-04-01	95649