Quarter	Millions of US Dollars
1971-01-01	11
1971-04-01	11
1971-07-01	12
1971-10-01	12
1972-01-01	12
1972-04-01	39
1972-07-01	38
1972-10-01	39
1973-01-01	70
1973-04-01	167
1973-07-01	166
1973-10-01	160
1974-01-01	170
1974-04-01	171
1974-07-01	169
1974-10-01	182
1975-01-01	183
1975-04-01	183
1975-07-01	210
1975-10-01	235
1976-01-01	239
1976-04-01	235
1976-07-01	311
1976-10-01	426
1977-01-01	440
1977-04-01	437
1977-07-01	503
1977-10-01	567
1978-01-01	586
1978-04-01	585
1978-07-01	653
1978-10-01	648
1979-01-01	662
1979-04-01	667
1979-07-01	1669
1979-10-01	2188
1980-01-01	1972
1980-04-01	2168
1980-07-01	2117
1980-10-01	2059
1981-01-01	2023
1981-04-01	1838
1981-07-01	1857
1981-10-01	1959
1982-01-01	1892
1982-04-01	1885
1982-07-01	1876
1982-10-01	1989
1983-01-01	2134
1983-04-01	2223
1983-07-01	2244
1983-10-01	2535
1984-01-01	2726
1984-04-01	2686
1984-07-01	3010
1984-10-01	3418
1985-01-01	3870
1985-04-01	4181
1985-07-01	4998
1985-10-01	5310
1986-01-01	6579
1986-04-01	7455
1986-07-01	8395
1986-10-01	8997
1987-01-01	9397
1987-04-01	9469
1987-07-01	9995
1987-10-01	10762
1988-01-01	11016
1988-04-01	10924
1988-07-01	11844
1988-10-01	12369
1989-01-01	12326
1989-04-01	12305
1989-07-01	12716
1989-10-01	12349
1990-01-01	12505
1990-04-01	14258
1990-07-01	14278
1990-10-01	15183
1991-01-01	16180
1991-04-01	16448
1991-07-01	16943
1991-10-01	17891
1992-01-01	16438
1992-04-01	17251
1992-07-01	17391
1992-10-01	16974
1993-01-01	16828
1993-04-01	17303
1993-07-01	17049
1993-10-01	17066
1994-01-01	17840
1994-04-01	18539
1994-07-01	19552
1994-10-01	20779
1995-01-01	23587
1995-04-01	24720
1995-07-01	24931
1995-10-01	24451
1996-01-01	22920
1996-04-01	22448
1996-07-01	20672
1996-10-01	18929
1997-01-01	17972
1997-04-01	18404
1997-07-01	19549
1997-10-01	19839
1998-01-01	19085
1998-04-01	17654
1998-07-01	17947
1998-10-01	18236
1999-01-01	17203
1999-04-01	16567
1999-07-01	17600
1999-10-01	15624
2000-01-01	15460
2000-04-01	16509
2000-07-01	19394
2000-10-01	17258
2001-01-01	24273
2001-04-01	27176
2001-07-01	28481
2001-10-01	26969
2002-01-01	30234
2002-04-01	33204
2002-07-01	32531
2002-10-01	34856
2003-01-01	36747
2003-04-01	38861
2003-07-01	39695
2003-10-01	42862
2004-01-01	42829
2004-04-01	43555
2004-07-01	46571
2004-10-01	49797
2005-01-01	48118
2005-04-01	45799
2005-07-01	45130
2005-10-01	44804
2006-01-01	50806
2006-04-01	54064
2006-07-01	48828
2006-10-01	57120
2007-01-01	63233
2007-04-01	79027
2007-07-01	81263
2007-10-01	87851
2008-01-01	88715
2008-04-01	104758
2008-07-01	93951
2008-10-01	113918
2009-01-01	118742
2009-04-01	145172
2009-07-01	150759
2009-10-01	155393
2010-01-01	152913
2010-04-01	144138
2010-07-01	167247
2010-10-01	161255
2011-01-01	171683
2011-04-01	174877
2011-07-01	157050
2011-10-01	150370
2012-01-01	146805
2012-04-01	142155
2012-07-01	148319
2012-10-01	151220
2013-01-01	147823
2013-04-01	153432
2013-07-01	167020
2013-10-01	173681
2014-01-01	169718
2014-04-01	167630
2014-07-01	155499
2014-10-01	151886
2015-01-01	138751
2015-04-01	146508
2015-07-01	145718
2015-10-01	145890
2016-01-01	159518
2016-04-01	155424
2016-07-01	159608
2016-10-01	151264
2017-01-01	150906
2017-04-01	161695
2017-07-01	167782
2017-10-01	169682
2018-01-01	173942
2018-04-01	163962