Quarter	Millions of US Dollars
1996-04-01	220
1996-07-01	545
1996-10-01	410
1997-01-01	410
1997-04-01	635
1997-07-01	632
1997-10-01	625
1998-01-01	619
1998-04-01	1167
1998-07-01	1222
1998-10-01	1216
1999-01-01	1580
1999-04-01	1530
1999-07-01	1568
1999-10-01	1495
2000-01-01	1823
2000-04-01	1819
2000-07-01	1700
2000-10-01	1778
2001-01-01	1795
2001-04-01	2116
2001-07-01	1924
2001-10-01	1855
2002-01-01	1837
2002-04-01	2090
2002-07-01	2066
2002-10-01	2191
2003-01-01	2275
2003-04-01	2380
2003-07-01	2426
2003-10-01	2623
2004-01-01	2540
2004-04-01	2273
2004-07-01	2320
2004-10-01	2540
2005-01-01	2419
2005-04-01	1649
2005-07-01	1642
2005-10-01	1605
2006-01-01	1646
2006-04-01	1724
2006-07-01	1717
2006-10-01	1778
2007-01-01	3130
2007-04-01	3174
2007-07-01	3332
2007-10-01	3459
2008-01-01	5297
2008-04-01	5281
2008-07-01	4792
2008-10-01	4662
2009-01-01	3926
2009-04-01	4170
2009-07-01	4320
2009-10-01	4250
2010-01-01	3302
2010-04-01	3006
2010-07-01	3344
2010-10-01	3274
2011-01-01	3481
2011-04-01	2891
2011-07-01	2701
2011-10-01	2588
2012-01-01	2671
2012-04-01	2518
2012-07-01	2586
2012-10-01	4889
2013-01-01	4811
2013-04-01	8366
2013-07-01	8451
2013-10-01	8508
2014-01-01	12008
2014-04-01	14713
2014-07-01	14283
2014-10-01	14106
2015-01-01	13554
2015-04-01	13726
2015-07-01	13731
2015-10-01	13605
2016-01-01	13946
2016-04-01	13830
2016-07-01	13854
2016-10-01	13598
2017-01-01	13660
2017-04-01	13957
2017-07-01	14120
2017-10-01	12998
2018-01-01	11868
2018-04-01	10727