Year	Percent
1975-01-01	33.702200000000000
1976-01-01	35.808000000000000
1977-01-01	37.012300000000000
1978-01-01	34.904200000000000
1979-01-01	33.765600000000000
1980-01-01	34.378500000000000
1981-01-01	35.487100000000000
1982-01-01	32.592000000000000
1983-01-01	34.914800000000000
1984-01-01	36.617700000000000
1985-01-01	38.521500000000000
1986-01-01	46.172600000000000
1987-01-01	38.952800000000000
1988-01-01	29.434800000000000
1989-01-01	27.698300000000000
1990-01-01	25.588100000000000
1991-01-01	27.911900000000000
1992-01-01	31.530000000000000
1993-01-01	33.565800000000000
1994-01-01	35.889100000000000
1995-01-01	36.792700000000000
1996-01-01	35.836400000000000
1997-01-01	37.376800000000000
1998-01-01	42.680500000000000
1999-01-01	43.196999999999996
2000-01-01	39.423600000000000
2001-01-01	39.423600000000000
2002-01-01	39.423600000000000
2003-01-01	39.423600000000000
2004-01-01	43.674700000000000
2005-01-01	40.109900000000000
2006-01-01	41.511000000000000
2007-01-01	46.303600000000000
2008-01-01	54.428900000000000
2009-01-01	71.475800000000000
2010-01-01	65.884200000000000
2011-01-01	64.638300000000000
2012-01-01	67.616300000000000
2013-01-01	67.990600000000000
2014-01-01	66.051300000000000
2015-01-01	71.423100000000000