Year Number 2004-01-01 3.109658814 2005-01-01 3.224090408 2006-01-01 3.694391669 2007-01-01 3.398260304 2008-01-01 3.797373562 2009-01-01 3.685004322 2012-01-01 2.917068709 2013-01-01 2.682737891 2014-01-01 2.464550757