Year	Percent
1984-01-01	38.615400000000000
1985-01-01	39.428200000000000
1986-01-01	43.530900000000000
1987-01-01	43.913000000000004
1988-01-01	46.773999999999994
1989-01-01	48.290000000000000
1990-01-01	47.930500000000000
1991-01-01	46.190100000000000
1992-01-01	45.243700000000000
1993-01-01	45.542700000000000
1994-01-01	42.449700000000000
1995-01-01	44.976000000000006
1996-01-01	47.993600000000000
1997-01-01	45.240400000000000
1998-01-01	44.075700000000000
1999-01-01	28.391800000000000
2000-01-01	29.864200000000000
2001-01-01	28.476300000000000
2002-01-01	24.659300000000000
2003-01-01	22.638600000000000
2004-01-01	21.188700000000000
2005-01-01	20.006600000000000
2006-01-01	19.384500000000000
2007-01-01	20.245000000000000
2008-01-01	22.515100000000000
2009-01-01	26.733600000000000
2010-01-01	30.984100000000000
2011-01-01	30.521100000000000
2012-01-01	28.440600000000000
2013-01-01	29.244900000000000
2014-01-01	29.663800000000000
2015-01-01	28.921200000000000
2016-01-01	27.662800000000000