Year	Percent
1969-01-01	33.235700000000000
1970-01-01	24.774000000000000
1971-01-01	23.072100000000000
1972-01-01	22.540500000000000
1973-01-01	22.249500000000000
1974-01-01	20.885100000000000
1975-01-01	23.920100000000000
1976-01-01	24.554900000000000
1977-01-01	25.367600000000000
1978-01-01	24.093600000000000
1979-01-01	23.062800000000000
1980-01-01	22.360600000000000
1981-01-01	24.653200000000000
1982-01-01	24.911600000000000
1983-01-01	25.943700000000000
1984-01-01	27.206600000000000
1985-01-01	27.406400000000000
1986-01-01	28.247900000000000
1987-01-01	29.760600000000000
1988-01-01	31.983500000000000
1989-01-01	30.478100000000000
1990-01-01	33.958000000000000
1991-01-01	37.127200000000000
1992-01-01	39.439100000000000
1993-01-01	42.300700000000000
1994-01-01	43.200600000000000
1995-01-01	44.500700000000000
1996-01-01	45.214300000000000
1997-01-01	45.831800000000000
1998-01-01	48.282100000000000
1999-01-01	48.500600000000000
2000-01-01	51.206100000000000
2001-01-01	53.376999999999995
2002-01-01	51.824300000000000
2003-01-01	54.289100000000000
2004-01-01	56.255700000000000
2005-01-01	56.901500000000000
2006-01-01	59.974600000000000
2007-01-01	62.143200000000000
2008-01-01	67.972000000000000
2009-01-01	73.625600000000000
2010-01-01	74.392800000000000
2011-01-01	77.115300000000000
2012-01-01	72.681800000000000
2013-01-01	71.173300000000000
2014-01-01	71.226200000000000
2015-01-01	69.711100000000000
2016-01-01	72.355800000000000