Year Number 2004-01-01 11.6289 2005-01-01 12.1948 2006-01-01 11.8555 2007-01-01 12.4181 2008-01-01 13.0265 2009-01-01 21.1695 2010-01-01 26.3263 2011-01-01 31.5116 2012-01-01 41.7063 2013-01-01 47.6770