Year Number 2004-01-01 6.9909 2005-01-01 11.7221 2006-01-01 14.2024 2007-01-01 15.0367 2008-01-01 18.4064 2009-01-01 18.4777 2010-01-01 21.1529 2011-01-01 21.6994 2012-01-01 25.0797 2013-01-01 26.1244 2014-01-01 31.6036 2015-01-01 31.2481 2016-01-01 31.1584