Year Percent 1973-01-01 81.71460000000000 1974-01-01 68.29110000000000 1975-01-01 67.32580000000000 1976-01-01 68.03350000000000 1977-01-01 88.40930000000000 1978-01-01 117.35100000000000 1979-01-01 126.30900000000000 1980-01-01 123.23200000000001 1981-01-01 115.44500000000000 1982-01-01 108.13500000000000 1983-01-01 101.65299999999999 1984-01-01 86.36790000000000 1985-01-01 73.91160000000000 1986-01-01 73.10870000000000 1987-01-01 75.01240000000000 1988-01-01 76.86650000000000 1989-01-01 77.61010000000000 1990-01-01 82.14630000000000 1991-01-01 84.51350000000000 1992-01-01 82.69020000000000 1993-01-01 87.61550000000000 1994-01-01 93.09920000000000 1995-01-01 94.99170000000000 1996-01-01 97.13410000000000 1997-01-01 100.73899999999999 1998-01-01 108.04000000000000 1999-01-01 111.69900000000000 2000-01-01 106.14700000000000 2001-01-01 95.25110000000000 2002-01-01 89.76810000000000 2003-01-01 89.15770000000000 2004-01-01 88.18120000000000 2005-01-01 91.80150000000000 2006-01-01 102.19200000000001 2007-01-01 99.91820000000000 2008-01-01 110.30000000000000 2009-01-01 116.61700000000000 2010-01-01 108.79700000000001 2011-01-01 105.16700000000000 2012-01-01 103.17200000000001 2013-01-01 92.89460000000000 2014-01-01 87.07320000000000 2015-01-01 89.65270000000000 2016-01-01 92.63250000000000