Quarter	Millions of US Dollars
1989-01-01	8520
1989-04-01	8621
1989-07-01	10516
1989-10-01	9318
1990-01-01	10840
1990-04-01	11269
1990-07-01	11644
1990-10-01	10967
1991-01-01	11405
1991-04-01	12310
1991-07-01	13728
1991-10-01	12085
1992-01-01	14072
1992-04-01	13272
1992-07-01	13026
1992-10-01	12001
1993-01-01	11896
1993-04-01	11962
1993-07-01	11299
1993-10-01	10598
1994-01-01	10409
1994-04-01	10988
1994-07-01	12122
1994-10-01	11788
1995-01-01	11307
1995-04-01	11302
1995-07-01	12939
1995-10-01	13101
1996-01-01	12952
1996-04-01	13500
1996-07-01	13733
1996-10-01	12574
1997-01-01	12529
1997-04-01	13365
1997-07-01	14632
1997-10-01	13836
1998-01-01	16301
1998-04-01	16118
1998-07-01	15720
1998-10-01	12883
1999-01-01	14237
1999-04-01	14211
1999-07-01	14039
1999-10-01	14039
2000-01-01	15542
2000-04-01	16276
2000-07-01	17180
2000-10-01	17465
2001-01-01	12982
2001-04-01	13697
2001-07-01	14177
2001-10-01	13093
2002-01-01	14205
2002-04-01	13525
2002-07-01	13259
2002-10-01	11935
2003-01-01	11272
2003-04-01	11879
2003-07-01	12097
2003-10-01	11412
2004-01-01	10636
2004-04-01	10613
2004-07-01	11455
2004-10-01	12298
2005-01-01	12065
2005-04-01	10640
2005-07-01	11888
2005-10-01	11284
2006-01-01	9153
2006-04-01	10146
2006-07-01	10266
2006-10-01	10581
2007-01-01	10242
2007-04-01	10104
2007-07-01	9896
2007-10-01	11275
2008-01-01	13557
2008-04-01	13034
2008-07-01	12795
2008-10-01	8812
2009-01-01	10028
2009-04-01	10050
2009-07-01	9719
2009-10-01	10764
2010-01-01	10566
2010-04-01	10883
2010-07-01	10487
2010-10-01	12419
2011-01-01	11543
2011-04-01	11913
2011-07-01	12692
2011-10-01	10435
2012-01-01	12014
2012-04-01	9401
2012-07-01	8953
2012-10-01	9965
2013-01-01	11619
2013-04-01	11987
2013-07-01	11301
2013-10-01	10115
2014-01-01	11485
2014-04-01	10461
2014-07-01	11924
2014-10-01	11335
2015-01-01	9415
2015-04-01	8321
2015-07-01	7658
2015-10-01	8217
2016-01-01	9525
2016-04-01	7680
2016-07-01	5793
2016-10-01	5414
2017-01-01	5791
2017-04-01	6498
2017-07-01	8158
2017-10-01	6847
2018-01-01	7864