Quarter Millions of US Dollars 2001-10-01 7011 2002-10-01 9062 2003-10-01 11556 2004-10-01 13520 2005-10-01 12733 2006-10-01 15412 2007-01-01 15945 2007-04-01 16570 2007-07-01 17294 2007-10-01 18207 2008-01-01 19576 2008-04-01 19024 2008-07-01 17246 2008-10-01 17437 2009-01-01 15787 2009-04-01 17954 2009-07-01 18499 2009-10-01 20438 2010-01-01 19357 2010-04-01 17970 2010-07-01 21881 2010-10-01 21538 2011-01-01 23256 2011-04-01 23000 2011-07-01 23151 2011-10-01 22791 2012-01-01 24437 2012-04-01 24640 2012-07-01 25306 2012-10-01 26999 2013-01-01 26920 2013-04-01 29112 2013-07-01 30072 2013-10-01 32602 2014-01-01 33382 2014-04-01 33574 2014-07-01 31310 2014-10-01 31457 2015-01-01 29881 2015-04-01 30823 2015-07-01 30794 2015-10-01 30454 2016-01-01 32276 2016-04-01 31405 2016-07-01 32284 2016-10-01 31165 2017-01-01 33344 2017-04-01 33197 2017-07-01 33873 2017-10-01 36210 2018-01-01 36939