Quarter	Millions of US Dollars
1972-07-01	31
1972-10-01	91
1973-01-01	95
1973-04-01	126
1973-07-01	126
1973-10-01	158
1974-01-01	161
1974-04-01	159
1974-07-01	156
1974-10-01	185
1975-01-01	222
1975-04-01	222
1975-07-01	216
1975-10-01	216
1976-01-01	218
1976-04-01	267
1976-07-01	312
1976-10-01	505
1977-01-01	591
1977-04-01	798
1977-07-01	1042
1977-10-01	1568
1978-01-01	1861
1978-04-01	2047
1978-07-01	2420
1978-10-01	2650
1979-01-01	2763
1979-04-01	2806
1979-07-01	3130
1979-10-01	3282
1980-01-01	3010
1980-04-01	3554
1980-07-01	3586
1980-10-01	3477
1981-01-01	3321
1981-04-01	3050
1981-07-01	3129
1981-10-01	3210
1982-01-01	2992
1982-04-01	2835
1982-07-01	2704
1982-10-01	2931
1983-01-01	2875
1983-04-01	2788
1983-07-01	2764
1983-10-01	2657
1984-01-01	2748
1984-04-01	2497
1984-07-01	2320
1984-10-01	2116
1985-01-01	2237
1985-04-01	2316
1985-07-01	2675
1985-10-01	2338
1986-01-01	2603
1986-04-01	2738
1986-07-01	2882
1986-10-01	2757
1987-01-01	2831
1987-04-01	2775
1987-07-01	2512
1987-10-01	2599
1988-01-01	2538
1988-04-01	1945
1988-07-01	1595
1988-10-01	1590
1989-01-01	1302
1989-04-01	1195
1989-07-01	2234
1989-10-01	2111
1990-01-01	2070
1990-04-01	2066
1990-07-01	2089
1990-10-01	2041
1991-01-01	2082
1991-04-01	1965
1991-07-01	2371
1991-10-01	3398
1992-01-01	3914
1992-04-01	5742
1992-07-01	5935
1992-10-01	5999
1993-01-01	6298
1993-04-01	7801
1993-07-01	9337
1993-10-01	11343
1994-01-01	12093
1994-04-01	55223
1994-07-01	55425
1994-10-01	56737
1995-01-01	56732
1995-04-01	57950
1995-07-01	59539
1995-10-01	60927
1996-01-01	64099
1996-04-01	70500
1996-07-01	68109
1996-10-01	71619
1997-01-01	72436
1997-04-01	77920
1997-07-01	82236
1997-10-01	80311
1998-01-01	84383
1998-04-01	88100
1998-07-01	86569
1998-10-01	75085
1999-01-01	71744
1999-04-01	73874
1999-07-01	75546
1999-10-01	79444
2000-01-01	84380
2000-04-01	80109
2000-07-01	86530
2000-10-01	87253
2001-01-01	88407
2001-04-01	83388
2001-07-01	83944
2001-10-01	82420
2002-01-01	85223
2002-04-01	88994
2002-07-01	89896
2002-10-01	89879
2003-01-01	92286
2003-04-01	96917
2003-07-01	100700
2003-10-01	105560
2004-01-01	107381
2004-04-01	103767
2004-07-01	105488
2004-10-01	106685
2005-01-01	107757
2005-04-01	106266
2005-07-01	107271
2005-10-01	108793
2006-01-01	112366
2006-04-01	102528
2006-07-01	104951
2006-10-01	111731
2007-01-01	116175
2007-04-01	121787
2007-07-01	117908
2007-10-01	120937
2008-01-01	125018
2008-04-01	127713
2008-07-01	122869
2008-10-01	119483
2009-01-01	118521
2009-04-01	121727
2009-07-01	130545
2009-10-01	141747
2010-01-01	148953
2010-04-01	155255
2010-07-01	169235
2010-10-01	175396
2011-01-01	186440
2011-04-01	200518
2011-07-01	198699
2011-10-01	207328
2012-01-01	233219
2012-04-01	239532
2012-07-01	248716
2012-10-01	263790
2013-01-01	270444
2013-04-01	286962
2013-07-01	290522
2013-10-01	294062
2014-01-01	308862
2014-04-01	323095
2014-07-01	326424
2014-10-01	319436
2015-01-01	301870
2015-04-01	305913
2015-07-01	295765
2015-10-01	291124
2016-01-01	283192
2016-04-01	287456
2016-07-01	289583
2016-10-01	287272
2017-01-01	286986
2017-04-01	286848
2017-07-01	290263
2017-10-01	295241
2018-01-01	291687
2018-04-01	281391