Year Percent 1989-01-01 2.7135800000000000 1990-01-01 1.6704200000000000 1991-01-01 1.4240000000000002 1992-01-01 2.8524000000000000 1993-01-01 4.3728700000000000 1994-01-01 4.8521400000000000 1995-01-01 5.6062800000000000 1996-01-01 7.3224100000000005 1997-01-01 8.0330500000000000 1998-01-01 10.4148000000000000 1999-01-01 15.0175000000000000 2000-01-01 16.6484000000000000 2001-01-01 19.4291000000000000 2002-01-01 19.1741000000000000 2003-01-01 23.4928000000000000 2004-01-01 24.9069000000000000 2005-01-01 26.8862000000000000 2006-01-01 26.5546000000000000 2007-01-01 24.0700000000000000 2008-01-01 20.0297000000000000 2009-01-01 25.7949000000000000 2010-01-01 25.2387000000000000 2011-01-01 23.1740000000000000 2012-01-01 23.8828000000000000 2013-01-01 24.2000000000000000 2014-01-01 21.6369000000000000 2015-01-01 21.5813000000000000 2016-01-01 27.4122000000000000