Year Number 2004-01-01 2.533983664 2005-01-01 3.755523523 2006-01-01 4.710963460 2007-01-01 5.238120836 2008-01-01 6.166342154 2009-01-01 6.872746185 2010-01-01 7.183739148 2011-01-01 10.788094440 2012-01-01 10.611856470 2013-01-01 6.935712450 2014-01-01 11.949098350