Year Percent 1982-01-01 15.343900000000000 1983-01-01 16.191400000000000 1984-01-01 17.536800000000000 1985-01-01 19.088600000000000 1986-01-01 20.651200000000000 1987-01-01 35.716900000000000 1988-01-01 47.352800000000000 1989-01-01 44.356700000000000 1990-01-01 45.151500000000000 1991-01-01 40.860600000000000 1992-01-01 33.334100000000000 1993-01-01 27.758500000000000 1994-01-01 23.943600000000000 1995-01-01 21.545700000000000 1996-01-01 20.127900000000000 1997-01-01 20.725100000000000 1998-01-01 22.110800000000000 1999-01-01 23.553100000000000 2000-01-01 27.140100000000000 2001-01-01 30.559500000000000 2002-01-01 31.901600000000000 2003-01-01 36.658600000000000 2004-01-01 42.095700000000000 2005-01-01 46.406200000000000 2006-01-01 50.275300000000000 2007-01-01 56.454300000000000 2008-01-01 63.709400000000000 2009-01-01 66.049700000000000 2010-01-01 60.086700000000000 2011-01-01 58.983300000000000 2012-01-01 55.252600000000000 2013-01-01 47.558900000000000 2014-01-01 43.239000000000000 2015-01-01 38.530500000000000 2016-01-01 34.321999999999996