Year Percent 1973-01-01 7.173220000000000 1974-01-01 7.870080000000001 1975-01-01 10.988200000000000 1976-01-01 14.123400000000000 1977-01-01 17.322300000000000 1978-01-01 20.673800000000000 1979-01-01 19.922800000000000 1980-01-01 17.813300000000000 1981-01-01 18.659600000000000 1982-01-01 22.653800000000000 1983-01-01 26.537800000000000 1984-01-01 27.523900000000000 1985-01-01 29.981700000000000 1986-01-01 39.841600000000000 1987-01-01 37.717000000000000 1988-01-01 40.274200000000000 1989-01-01 37.376800000000000 1990-01-01 30.646500000000000 1991-01-01 32.345900000000000 1992-01-01 33.372900000000000 1993-01-01 35.366100000000000 1994-01-01 36.765800000000000 1995-01-01 36.952200000000000 1996-01-01 35.450100000000000 1997-01-01 35.556000000000000 1998-01-01 41.721600000000000 1999-01-01 41.395900000000000 2000-01-01 35.352100000000000 2001-01-01 37.562200000000000 2002-01-01 39.078400000000000 2003-01-01 40.281900000000000 2004-01-01 41.438500000000000 2005-01-01 45.790900000000000 2006-01-01 58.097500000000000 2007-01-01 59.091200000000000 2008-01-01 70.040900000000000 2009-01-01 101.231000000000010 2010-01-01 92.571800000000000 2011-01-01 79.741200000000000 2012-01-01 78.760700000000000 2013-01-01 80.760600000000000 2014-01-01 85.825500000000000 2015-01-01 106.187999999999990 2016-01-01 116.131000000000000