Year	Percent
1980-01-01	11.606400000000000
1981-01-01	16.493200000000000
1982-01-01	18.707700000000000
1983-01-01	23.156100000000000
1984-01-01	22.505300000000000
1985-01-01	22.035600000000000
1986-01-01	15.510600000000000
1987-01-01	28.471700000000000
1988-01-01	33.421500000000000
1989-01-01	64.159700000000000
1990-01-01	18.069200000000000
1991-01-01	16.869700000000000
1992-01-01	23.340100000000000
1993-01-01	30.686300000000000
1994-01-01	15.159800000000000
1995-01-01	11.412700000000000
1996-01-01	15.599900000000000
1997-01-01	17.938000000000000
1998-01-01	26.593400000000000
1999-01-01	34.922500000000000
2000-01-01	35.273600000000000
2001-01-01	34.488100000000000
2002-01-01	31.959800000000000
2003-01-01	37.114300000000000
2004-01-01	37.368000000000000
2005-01-01	40.890900000000000
2006-01-01	41.087100000000000
2007-01-01	38.685300000000000
2008-01-01	34.553400000000000
2009-01-01	36.794000000000004
2010-01-01	35.903100000000000
2011-01-01	36.447600000000000
2012-01-01	37.234000000000000
2013-01-01	34.622000000000000
2014-01-01	33.794000000000004
2015-01-01	39.999700000000000
2016-01-01	44.390900000000000