Quarter	Millions of US Dollars
1990-01-01	11764
1990-04-01	12441
1990-07-01	13420
1990-10-01	12755
1991-01-01	11996
1991-04-01	12449
1991-07-01	13239
1991-10-01	12792
1992-01-01	13111
1992-04-01	13729
1992-07-01	13618
1992-10-01	13231
1993-01-01	13707
1993-04-01	14762
1993-07-01	15513
1993-10-01	15548
1994-01-01	15738
1994-04-01	16908
1994-07-01	18181
1994-10-01	19164
1995-01-01	18958
1995-04-01	19513
1995-07-01	20055
1995-10-01	19780
1996-01-01	19970
1996-04-01	21169
1996-07-01	22385
1996-10-01	21910
1997-01-01	19925
1997-04-01	19820
1997-07-01	18919
1997-10-01	17342
1998-01-01	15789
1998-04-01	15886
1998-07-01	15395
1998-10-01	16456
1999-01-01	16667
1999-04-01	16699
1999-07-01	16497
1999-10-01	16573
2000-01-01	15000
2000-04-01	14466
2000-07-01	12739
2000-10-01	14240
2001-01-01	12361
2001-04-01	13008
2001-07-01	13495
2001-10-01	13811
2002-01-01	14230
2002-04-01	16258
2002-07-01	15935
2002-10-01	18300
2003-01-01	19341
2003-04-01	19269
2003-07-01	21533
2003-10-01	23849
2004-01-01	23798
2004-04-01	20499
2004-07-01	22747
2004-10-01	24848
2005-01-01	22925
2005-04-01	22890
2005-07-01	23144
2005-10-01	23385
2006-01-01	19794
2006-04-01	20012
2006-07-01	20756
2006-10-01	20346
2007-01-01	20501
2007-04-01	22539
2007-07-01	22665
2007-10-01	23528
2008-01-01	23788
2008-04-01	23196
2008-07-01	19496
2008-10-01	18195
2009-01-01	20031
2009-04-01	25262
2009-07-01	29171
2009-10-01	30568
2010-01-01	31629
2010-04-01	32398
2010-07-01	37171
2010-10-01	43180
2011-01-01	45658
2011-04-01	53736
2011-07-01	52376
2011-10-01	50618
2012-01-01	55239
2012-04-01	57425
2012-07-01	60621
2012-10-01	63425
2013-01-01	65154
2013-04-01	54497
2013-07-01	59506
2013-10-01	62768
2014-01-01	65675
2014-04-01	65743
2014-07-01	59801
2014-10-01	62661
2015-01-01	61469
2015-04-01	52413
2015-07-01	48806
2015-10-01	53967
2016-01-01	53817
2016-04-01	57104
2016-07-01	59388
2016-10-01	56335
2017-01-01	57297
2017-04-01	60182
2017-07-01	60022
2017-10-01	56073
2018-01-01	58907