Year Percent 1993-01-01 2.1216500000000000 1994-01-01 3.8135100000000000 1995-01-01 3.9100099999999998 1996-01-01 5.4498000000000000 1997-01-01 6.4006099999999995 1998-01-01 6.2143600000000000 1999-01-01 6.2481100000000000 2000-01-01 8.1074899999999990 2001-01-01 9.4449200000000000 2002-01-01 11.2733000000000000 2003-01-01 12.2948000000000000 2004-01-01 13.1350000000000000 2005-01-01 13.3405000000000000 2006-01-01 15.1952000000000000 2007-01-01 20.4869000000000000 2008-01-01 24.7244000000000000 2009-01-01 26.3240000000000000 2010-01-01 31.3688000000000000 2011-01-01 32.0962000000000000 2012-01-01 36.3497000000000000 2013-01-01 44.2836000000000000 2014-01-01 52.0176000000000000 2015-01-01 58.8903000000000000 2016-01-01 64.0463000000000000