Quarter	Millions of US Dollars
1999-04-01	155
1999-07-01	160
1999-10-01	226
2000-01-01	215
2000-04-01	215
2000-07-01	197
2000-10-01	209
2001-01-01	199
2001-04-01	191
2001-07-01	205
2001-10-01	375
2002-01-01	371
2002-04-01	424
2002-07-01	419
2002-10-01	446
2003-01-01	463
2003-04-01	486
2003-07-01	495
2003-10-01	537
2004-01-01	520
2004-04-01	729
2004-07-01	745
2004-10-01	824
2005-01-01	784
2005-04-01	852
2005-07-01	849
2005-10-01	832
2006-01-01	853
2006-04-01	1151
2006-07-01	1146
2006-10-01	1185
2007-01-01	1199
2007-04-01	1215
2007-07-01	1276
2007-10-01	1325
2008-01-01	2056
2008-04-01	1892
2008-07-01	1716
2008-10-01	1392
2009-01-01	1331
2009-04-01	1413
2009-07-01	1464
2009-10-01	1441
2010-01-01	1348
2010-04-01	1227
2010-07-01	1365
2010-10-01	1336
2011-01-01	1421
2011-04-01	1656
2011-07-01	1580
2011-10-01	1535
2012-01-01	2568
2012-04-01	2507
2012-07-01	2534
2012-10-01	3806
2013-01-01	3774
2013-04-01	3796
2013-07-01	3830
2013-10-01	3853
2014-01-01	6611
2014-04-01	7394
2014-07-01	5989
2014-10-01	5901
2015-01-01	5565
2015-04-01	5669
2015-07-01	6233
2015-10-01	6740
2016-01-01	6913
2016-04-01	7647
2016-07-01	7672
2016-10-01	8833
2017-01-01	8772
2017-04-01	10641
2017-07-01	10930
2017-10-01	11091
2018-01-01	10839
2018-04-01	11486