Year Number 2004-01-01 1.8883 2005-01-01 2.1859 2006-01-01 3.2221 2007-01-01 3.5823 2008-01-01 4.1510 2009-01-01 4.6026 2010-01-01 5.5767 2011-01-01 6.3006 2012-01-01 6.8075 2013-01-01 7.4887 2014-01-01 8.8763 2015-01-01 10.2670 2016-01-01 10.5862 2017-01-01 9.2298