Year Percent 1983-01-01 7.8026899999999990 1984-01-01 7.8269800000000010 1985-01-01 8.5893500000000000 1986-01-01 8.4565500000000000 1987-01-01 5.0951200000000000 1988-01-01 3.5669100000000000 1989-01-01 4.4083100000000000 1990-01-01 5.0886700000000000 1991-01-01 5.9343699999999995 1992-01-01 12.7456000000000000 1993-01-01 18.4257000000000000 1994-01-01 16.4509000000000000 1995-01-01 14.0864000000000000 1996-01-01 12.3800000000000000 1997-01-01 13.8366000000000000 1998-01-01 14.1447000000000000 1999-01-01 11.3261000000000000 2000-01-01 9.4852200000000000 2001-01-01 11.6021000000000000 2002-01-01 14.1606000000000000 2003-01-01 17.0902000000000000 2004-01-01 22.2812000000000000 2005-01-01 24.2017000000000000 2006-01-01 23.9407000000000000 2007-01-01 26.0338000000000000 2008-01-01 30.4957000000000000 2009-01-01 35.4860000000000000 2010-01-01 41.9098000000000000 2011-01-01 47.8660000000000100 2012-01-01 52.4146000000000000 2013-01-01 51.8882000000000000 2014-01-01 50.0508000000000000 2015-01-01 51.2535000000000000 2016-01-01 53.4210000000000100