Year Percent 1975-01-01 26.4305000000000000 1976-01-01 27.7038000000000000 1977-01-01 15.8742000000000000 1978-01-01 3.0729900000000003 1979-01-01 14.9573000000000000 1980-01-01 30.0857000000000000 1981-01-01 33.3317000000000000 1982-01-01 34.7629000000000000 1983-01-01 39.6169000000000000 1984-01-01 45.2337000000000000 1985-01-01 56.9207000000000000 1986-01-01 75.4691000000000000 1987-01-01 95.0346000000000000 1988-01-01 111.7080000000000000 1989-01-01 127.7270000000000000 1990-01-01 112.2520000000000100 1991-01-01 86.2063000000000000 1992-01-01 69.9660000000000100 1993-01-01 61.6637000000000000 1994-01-01 68.9726000000000000 1995-01-01 68.3470000000000000 1996-01-01 62.9754000000000000 1997-01-01 54.7391000000000000 1998-01-01 54.1331000000000000 1999-01-01 79.5932000000000000 2000-01-01 80.4366000000000000 2001-01-01 58.8365000000000000 2002-01-01 51.7552000000000000 2003-01-01 58.4013000000000000 2004-01-01 69.8628000000000000 2005-01-01 84.7512000000000000 2006-01-01 98.9617000000000000 2007-01-01 98.1964000000000000 2008-01-01 80.3854000000000000 2009-01-01 64.4049000000000000 2010-01-01 64.6110000000000000 2011-01-01 61.2892000000000000 2012-01-01 55.0323000000000000 2013-01-01 71.4735000000000000 2014-01-01 88.8581000000000000 2015-01-01 99.5242000000000000 2016-01-01 105.0179999999999900 2017-01-01 112.7720000000000000