Year Percent 1975-01-01 27.99570000000000 1976-01-01 26.37690000000000 1977-01-01 79.17580000000000 1978-01-01 78.64990000000000 1979-01-01 85.21300000000000 1980-01-01 95.98270000000000 1981-01-01 65.15700000000000 1982-01-01 64.02430000000000 1983-01-01 68.33880000000000 1984-01-01 69.52900000000000 1985-01-01 72.33010000000000 1986-01-01 82.86920000000000 1987-01-01 88.20970000000000 1988-01-01 87.46140000000000 1989-01-01 89.75900000000000 1990-01-01 85.66660000000000 1991-01-01 81.24320000000000 1992-01-01 79.56650000000000 1993-01-01 88.81880000000000 1994-01-01 97.88320000000000 1995-01-01 103.55300000000000 1996-01-01 123.85600000000001 1997-01-01 144.21700000000000 1998-01-01 160.94299999999998 1999-01-01 187.38900000000000 2000-01-01 150.55000000000000 2001-01-01 92.69030000000000 2002-01-01 99.10420000000000 2003-01-01 107.45800000000000 2004-01-01 105.71500000000000 2005-01-01 117.87100000000001 2006-01-01 125.50900000000000 2007-01-01 136.71400000000000 2008-01-01 105.96500000000000 2009-01-01 96.50870000000000 2010-01-01 125.21000000000000 2011-01-01 117.77500000000000 2012-01-01 109.23899999999999 2013-01-01 112.37299999999999 2014-01-01 114.32200000000000 2015-01-01 110.16600000000000 2016-01-01 115.69700000000000 2017-01-01 133.94700000000000