Year	Percent
1966-01-01	85.40330000000000
1967-01-01	80.41840000000000
1968-01-01	70.07790000000000
1969-01-01	80.36170000000000
1970-01-01	101.89100000000000
1971-01-01	103.67100000000000
1972-01-01	100.69800000000000
1973-01-01	107.66900000000000
1974-01-01	108.85300000000000
1975-01-01	97.06920000000000
1976-01-01	94.35040000000000
1977-01-01	94.74460000000000
1978-01-01	89.96690000000000
1979-01-01	84.46160000000000
1980-01-01	86.35220000000000
1981-01-01	91.68250000000000
1982-01-01	93.20570000000000
1983-01-01	93.11290000000000
1984-01-01	91.28740000000000
1985-01-01	86.29299999999999
1986-01-01	83.85950000000000
1987-01-01	82.06370000000000
1988-01-01	79.93210000000000
1989-01-01	84.19090000000000
1990-01-01	83.80400000000000
1991-01-01	80.81400000000000
1992-01-01	79.91360000000000
1993-01-01	76.11510000000000
1994-01-01	76.03500000000000
1995-01-01	79.68890000000000
1996-01-01	77.42510000000000
1997-01-01	75.09260000000000
1998-01-01	79.75370000000000
1999-01-01	83.47610000000000
2000-01-01	82.12890000000000
2001-01-01	73.69800000000001
2002-01-01	65.17190000000000
2003-01-01	61.97280000000000
2004-01-01	63.89220000000000
2005-01-01	66.35140000000000
2006-01-01	69.47750000000000
2007-01-01	67.14910000000000
2008-01-01	65.41010000000000
2009-01-01	69.11100000000000