Quarter	Millions of US Dollars
2002-01-01	53
2002-04-01	88
2002-07-01	168
2002-10-01	186
2003-01-01	199
2003-04-01	203
2003-07-01	225
2003-10-01	213
2004-01-01	177
2004-04-01	184
2004-07-01	213
2004-10-01	177
2005-01-01	167
2005-04-01	165
2005-07-01	164
2005-10-01	157
2006-01-01	155
2006-04-01	147
2006-07-01	139
2006-10-01	128
2007-01-01	139
2007-04-01	148
2007-07-01	164
2007-10-01	148
2008-01-01	114
2008-04-01	107
2008-07-01	136
2008-10-01	141
2009-01-01	170
2009-04-01	161
2009-07-01	112
2009-10-01	103
2010-01-01	82
2010-04-01	83
2010-07-01	84
2010-10-01	84
2011-01-01	122
2011-04-01	122
2011-07-01	126
2011-10-01	120
2012-01-01	81
2012-04-01	74
2012-07-01	54
2012-10-01	54
2013-01-01	53
2013-04-01	46
2013-07-01	47
2013-10-01	32
2014-01-01	13
2014-04-01	14
2014-07-01	14
2014-10-01	13
2015-01-01	14
2015-04-01	14
2015-07-01	14
2015-10-01	15
2016-01-01	15
2016-04-01	15
2016-07-01	16
2016-10-01	16
2017-01-01	17
2017-04-01	17
2017-07-01	17
2017-10-01	17
2018-01-01	17