Year	Percent
1973-01-01	10.110600000000000
1974-01-01	13.038100000000000
1975-01-01	18.538000000000000
1976-01-01	22.055000000000000
1977-01-01	18.145300000000000
1978-01-01	17.749300000000000
1979-01-01	17.789500000000000
1980-01-01	18.645900000000000
1981-01-01	19.015800000000000
1982-01-01	19.138600000000000
1983-01-01	18.406200000000000
1984-01-01	14.192500000000000
1985-01-01	12.383800000000000
1986-01-01	13.754400000000000
1987-01-01	13.906400000000000
1988-01-01	12.845100000000000
1989-01-01	10.593100000000000
1990-01-01	9.833610000000000
1991-01-01	9.686539999999999
1992-01-01	10.281700000000000
1993-01-01	10.250800000000000
1994-01-01	8.188950000000000
1995-01-01	8.091370000000000
1996-01-01	10.305300000000000
1997-01-01	11.222500000000000
1998-01-01	12.641800000000000
1999-01-01	13.468400000000000
2000-01-01	14.259200000000000
2001-01-01	14.023500000000000
2002-01-01	16.645700000000000
2003-01-01	19.452800000000000
2004-01-01	20.249300000000000
2005-01-01	19.256500000000000
2006-01-01	18.808500000000000
2007-01-01	19.121900000000000
2008-01-01	18.966200000000000
2009-01-01	18.109700000000000
2010-01-01	18.004300000000000
2011-01-01	17.958600000000000
2012-01-01	19.769600000000000
2013-01-01	20.865500000000000
2014-01-01	23.709200000000000
2015-01-01	26.839100000000000
2016-01-01	29.651100000000000