Year Percent 1994-01-01 1.7379200000000001 1995-01-01 2.5417000000000000 1996-01-01 3.5315600000000000 1997-01-01 4.1875400000000000 1998-01-01 4.7617300000000000 1999-01-01 5.0428200000000000 2000-01-01 10.0610000000000000 2001-01-01 10.6539000000000000 2002-01-01 13.4509000000000000 2003-01-01 18.8110000000000000 2004-01-01 18.5514000000000000 2005-01-01 18.8182000000000000 2006-01-01 19.2819000000000000 2007-01-01 17.7767000000000000 2008-01-01 15.9654000000000000 2009-01-01 16.2871000000000000 2010-01-01 14.2072000000000000 2011-01-01 11.3390000000000000 2012-01-01 10.7025000000000000