Year	Percent
1980-01-01	18.365300000000000
1981-01-01	16.416400000000000
1982-01-01	15.876600000000000
1983-01-01	15.104400000000000
1984-01-01	17.629300000000000
1985-01-01	17.351600000000000
1986-01-01	18.125600000000000
1987-01-01	16.547500000000000
1988-01-01	16.592000000000000
1989-01-01	15.613300000000000
1990-01-01	14.457100000000000
1991-01-01	11.735500000000000
1992-01-01	11.453900000000000
1993-01-01	12.625600000000000
1994-01-01	10.523200000000000
1995-01-01	9.255510000000001
1996-01-01	9.641440000000000
1997-01-01	7.507680000000001
1998-01-01	10.828900000000000
1999-01-01	5.847740000000000
2000-01-01	4.281760000000000
2001-01-01	7.916289999999999
2002-01-01	8.190890000000000
2003-01-01	9.149150000000000
2004-01-01	10.014400000000000
2005-01-01	10.177400000000000
2006-01-01	9.476180000000001
2007-01-01	9.926290000000000
2008-01-01	11.168900000000000
2009-01-01	19.085500000000000
2010-01-01	17.047300000000000
2011-01-01	14.427400000000000
2012-01-01	14.852200000000000
2013-01-01	14.275800000000000
2014-01-01	13.694900000000000
2015-01-01	14.185600000000000
2016-01-01	14.699000000000002