Year Percent 1973-01-01 17.01450000000000 1974-01-01 18.00140000000000 1975-01-01 17.92140000000000 1976-01-01 18.47100000000000 1977-01-01 20.86730000000000 1978-01-01 22.68480000000000 1979-01-01 24.38580000000000 1980-01-01 23.40750000000000 1981-01-01 22.93410000000000 1982-01-01 23.68450000000000 1983-01-01 24.35730000000000 1984-01-01 25.02770000000000 1985-01-01 28.42890000000000 1986-01-01 32.17230000000000 1987-01-01 36.72520000000000 1988-01-01 59.84850000000000 1989-01-01 81.86050000000000 1990-01-01 82.42060000000000 1991-01-01 84.12460000000000 1992-01-01 90.77710000000000 1993-01-01 94.20590000000000 1994-01-01 91.99420000000000 1995-01-01 94.38440000000000 1996-01-01 97.87410000000000 1997-01-01 102.31700000000001 1998-01-01 107.92900000000000 1999-01-01 114.80000000000000 2000-01-01 117.96200000000000 2001-01-01 118.58900000000000 2002-01-01 114.56600000000000 2003-01-01 114.75299999999999 2004-01-01 118.66600000000000 2005-01-01 123.87400000000000 2006-01-01 132.78600000000000 2007-01-01 140.47400000000000 2008-01-01 144.59300000000000 2009-01-01 150.59300000000000 2010-01-01 153.46300000000000