Year	Percent
1960-01-01	31.95910000000000
1961-01-01	31.99860000000000
1962-01-01	31.10560000000000
1963-01-01	31.04950000000000
1964-01-01	31.61950000000000
1965-01-01	31.69620000000000
1966-01-01	34.50890000000000
1967-01-01	39.11720000000000
1968-01-01	41.06980000000000
1969-01-01	41.55720000000000
1970-01-01	42.57950000000000
1971-01-01	42.73350000000000
1972-01-01	42.87810000000000
1973-01-01	43.21840000000000
1974-01-01	43.56380000000000
1975-01-01	45.33500000000000
1976-01-01	46.31750000000000
1977-01-01	49.20160000000000
1978-01-01	51.50160000000000
1979-01-01	53.11800000000000
1980-01-01	54.40190000000000
1981-01-01	58.43310000000000
1982-01-01	65.16280000000000
1983-01-01	61.82160000000000
1984-01-01	59.13600000000000
1985-01-01	58.56330000000000
1986-01-01	59.95600000000000
1987-01-01	59.79270000000000
1988-01-01	60.51850000000000
1989-01-01	64.11470000000000
1990-01-01	68.41460000000000
1991-01-01	72.73270000000000
1992-01-01	73.58310000000000
1993-01-01	73.52000000000000
1994-01-01	70.93500000000000
1995-01-01	71.56230000000000
1996-01-01	72.09940000000000
1997-01-01	71.39070000000000
1998-01-01	71.16530000000000
1999-01-01	68.63330000000000
2000-01-01	66.16040000000000
2001-01-01	108.75500000000000
2002-01-01	146.88800000000000
2003-01-01	141.63200000000000
2004-01-01	136.65900000000000
2005-01-01	138.46700000000000
2006-01-01	146.62600000000000
2007-01-01	128.75900000000000
2008-01-01	112.74600000000001