Year	Percent
1984-01-01	94.055700000000000
1985-01-01	90.089200000000000
1986-01-01	85.094900000000000
1987-01-01	83.115500000000000
1988-01-01	78.501300000000000
1989-01-01	78.852200000000000
1990-01-01	76.154500000000000
1991-01-01	71.469400000000000
1992-01-01	73.572100000000000
1993-01-01	75.119300000000000
1994-01-01	73.405700000000000
1995-01-01	76.651700000000000
1996-01-01	85.195900000000000
1997-01-01	92.711000000000000
1998-01-01	93.205700000000000
1999-01-01	64.333500000000000
2000-01-01	68.341000000000010
2001-01-01	64.410000000000000
2002-01-01	51.310200000000000
2003-01-01	41.786600000000000
2004-01-01	35.382000000000000
2005-01-01	31.480800000000000
2006-01-01	29.718800000000000
2007-01-01	31.318700000000000
2008-01-01	33.920000000000000
2009-01-01	35.957300000000000
2010-01-01	38.428200000000000
2011-01-01	41.146900000000000
2012-01-01	40.149200000000000
2013-01-01	39.501900000000000
2014-01-01	41.624700000000000
2015-01-01	39.638300000000000
2016-01-01	35.608000000000004