Year Percent 1992-01-01 43.4169000000000000 1993-01-01 21.3165000000000000 1994-01-01 3.5484699999999996 1995-01-01 5.5727100000000000 1996-01-01 6.2428500000000000 1997-01-01 6.3278200000000000 1998-01-01 7.6236600000000010 1999-01-01 9.4746700000000000 2000-01-01 10.4886000000000000 2001-01-01 10.1849000000000000 2002-01-01 8.9350700000000000 2003-01-01 7.7676000000000000 2004-01-01 7.8809000000000000 2005-01-01 8.8388200000000000 2006-01-01 9.5342300000000000 2007-01-01 11.9403000000000000 2008-01-01 17.0657000000000000 2009-01-01 25.0763000000000000 2010-01-01 28.3233000000000000 2011-01-01 34.0996000000000000 2012-01-01 38.6706000000000000 2013-01-01 43.9599000000000000 2014-01-01 47.5759000000000000 2015-01-01 49.8548000000000000 2016-01-01 51.6924000000000000