Quarter Billions of US Dollars 1998-07-01 0.0240 1998-10-01 0.0235 1999-01-01 0.0165 1999-04-01 0.0161 1999-07-01 0.0148 1999-10-01 0.0159 2000-01-01 0.0163 2000-04-01 0.0158 2000-07-01 0.0154 2000-10-01 0.0146 2001-01-01 0.0132 2001-04-01 0.0123 2004-01-01 0.0197 2004-04-01 0.1103 2004-07-01 0.1206 2004-10-01 0.4120 2005-01-01 1.1791 2005-04-01 2.3289 2005-07-01 4.6647 2005-10-01 5.4940 2006-01-01 7.1460 2006-04-01 7.6429 2006-07-01 8.5394 2006-10-01 10.7296 2007-01-01 13.6791 2007-04-01 19.0249 2007-07-01 20.8902 2007-10-01 21.5611 2008-01-01 22.6197 2008-04-01 25.4876 2008-07-01 21.3479 2008-10-01 17.2003 2009-01-01 17.5159 2009-04-01 19.3647 2009-07-01 22.6739 2009-10-01 23.9060 2010-01-01 24.5151 2010-04-01 26.8951 2010-07-01 30.6799 2010-10-01 35.0419 2011-01-01 40.2570 2011-04-01 48.6203 2011-07-01 45.8788 2011-10-01 46.3639 2012-01-01 47.7277 2012-04-01 44.4103 2012-07-01 46.4957 2012-10-01 47.4809 2013-01-01 50.0604 2013-04-01 47.2479 2013-07-01 48.7172 2013-10-01 47.5855 2014-01-01 49.5924 2014-04-01 52.9266 2014-07-01 48.0320 2014-10-01 44.4265 2015-01-01 36.4227 2015-04-01 36.8217