Year Percent 1960-01-01 43.99300000000000 1961-01-01 43.47270000000000 1962-01-01 44.38520000000000 1963-01-01 45.63350000000000 1964-01-01 43.67350000000000 1965-01-01 42.41810000000000 1966-01-01 43.11590000000000 1967-01-01 43.44990000000000 1968-01-01 44.87930000000000 1969-01-01 46.02940000000000 1970-01-01 42.48010000000000 1971-01-01 42.94390000000000 1972-01-01 43.92620000000000 1973-01-01 44.35290000000000 1974-01-01 43.98950000000000 1975-01-01 46.58490000000000 1976-01-01 47.14420000000000 1977-01-01 50.12380000000000 1978-01-01 52.03910000000000 1979-01-01 54.28720000000000 1980-01-01 54.98410000000000 1981-01-01 55.51250000000000 1982-01-01 57.48380000000000 1983-01-01 57.71300000000000 1984-01-01 57.93830000000000 1985-01-01 59.91290000000000 1986-01-01 61.48920000000000 1987-01-01 62.71130000000000 1988-01-01 62.92470000000000 1989-01-01 64.83110000000000 1990-01-01 67.12640000000000 1991-01-01 67.51680000000000 1992-01-01 68.33270000000000 1993-01-01 70.33630000000000 1994-01-01 69.11570000000000 1995-01-01 67.66370000000000 1996-01-01 68.61290000000000 1997-01-01 68.18460000000000 1998-01-01 68.18460000000000 1999-01-01 68.18460000000000 2000-01-01 87.61930000000000 2001-01-01 76.21340000000000 2002-01-01 76.39110000000000 2003-01-01 79.73530000000000 2004-01-01 82.18750000000000 2005-01-01 86.79520000000000 2006-01-01 91.66610000000000 2007-01-01 91.24990000000000 2008-01-01 91.64390000000000 2009-01-01 98.06400000000000 2010-01-01 97.01520000000000 2011-01-01 97.86790000000000 2012-01-01 98.69950000000000 2013-01-01 96.89720000000000 2014-01-01 99.41860000000000 2015-01-01 101.37100000000001 2016-01-01 99.00420000000000