Year	Percent
1966-01-01	52.160700000000000
1967-01-01	52.349500000000000
1968-01-01	58.053200000000000
1969-01-01	50.118600000000000
1970-01-01	53.373600000000000
1971-01-01	53.087400000000000
1972-01-01	56.098500000000000
1973-01-01	49.924400000000000
1974-01-01	42.113800000000000
1975-01-01	32.916300000000000
1976-01-01	32.593500000000000
1977-01-01	35.239500000000000
1978-01-01	36.472900000000000
1979-01-01	37.580400000000000
1980-01-01	35.032100000000000
1981-01-01	36.870400000000000
1982-01-01	39.685200000000000
1983-01-01	40.768600000000000
1984-01-01	40.641100000000000
1985-01-01	42.143400000000000
1986-01-01	41.814100000000000
1987-01-01	43.050500000000000
1988-01-01	46.091000000000000
1989-01-01	44.766400000000000
1990-01-01	47.369300000000000
1991-01-01	50.319500000000000
1992-01-01	53.587200000000000
1993-01-01	52.791300000000000
1994-01-01	53.373200000000000
1995-01-01	53.726600000000000
1996-01-01	56.193800000000000
1997-01-01	62.239700000000000
1998-01-01	56.861000000000004
1999-01-01	57.904200000000000
2000-01-01	60.349200000000000
2001-01-01	74.234700000000000
2002-01-01	89.363700000000000
2003-01-01	95.698700000000000
2004-01-01	95.776900000000000
2005-01-01	99.045400000000000
2006-01-01	100.117000000000000
2007-01-01	105.870000000000000
2008-01-01	117.673999999999990
2009-01-01	117.059000000000000