Year Percent 1972-01-01 65.20410000000000 1973-01-01 63.68380000000000 1974-01-01 65.47130000000000 1975-01-01 69.92840000000000 1976-01-01 72.02360000000000 1977-01-01 70.49430000000000 1978-01-01 67.04400000000000 1979-01-01 65.65060000000000 1980-01-01 66.40920000000000 1981-01-01 69.63060000000000 1982-01-01 71.69120000000000 1983-01-01 70.33650000000000 1984-01-01 65.90630000000000 1985-01-01 62.73210000000000 1986-01-01 60.67970000000000 1987-01-01 61.73820000000000 1988-01-01 66.18840000000000 1989-01-01 71.33900000000000 1990-01-01 73.13470000000000 1991-01-01 73.93700000000000 1992-01-01 74.82090000000000 1993-01-01 74.24700000000000 1994-01-01 70.77250000000000 1995-01-01 68.55970000000000 1996-01-01 68.94840000000000 1997-01-01 71.38100000000000 1998-01-01 76.98790000000000 1999-01-01 84.49340000000000 2000-01-01 90.13090000000000 2001-01-01 94.24820000000000 2002-01-01 94.11700000000000 2003-01-01 99.34050000000000 2004-01-01 107.38900000000000 2005-01-01 120.95100000000001 2006-01-01 140.68800000000000 2007-01-01 155.48300000000000 2008-01-01 167.25799999999998 2009-01-01 173.14700000000002 2010-01-01 170.23100000000000 2011-01-01 169.25200000000000 2012-01-01 163.74000000000000 2013-01-01 151.58400000000000 2014-01-01 136.55200000000002 2015-01-01 121.58100000000000 2016-01-01 111.57600000000001