Year	Percent
1986-01-01	65.9333316556785
1987-01-01	62.8977657413676
1988-01-01	58.4358613189157
1989-01-01	54.0932560801674
1990-01-01	53.7102440775932
1991-01-01	53.0507469975318
1992-01-01	52.0487103750629
1993-01-01	55.4224393795116
1994-01-01	59.0323015484512
1995-01-01	62.6636579715665
1996-01-01	65.6849990942638
1997-01-01	65.8106765632633
1998-01-01	66.7433290973599
1999-01-01	67.1961762604120
2000-01-01	67.8869158707598
2001-01-01	70.7133425916668
2002-01-01	74.5353820399767
2003-01-01	73.3395645071280
2004-01-01	76.1791301948154
2005-01-01	78.0356393921264
2006-01-01	79.5324702679618
2007-01-01	80.6707757686022
2008-01-01	79.8357928492461
2009-01-01	79.4954647910682
2010-01-01	79.4350436458195
2011-01-01	80.0907635326714
2012-01-01	79.5824631745733
2013-01-01	79.2899709610519
2014-01-01	80.7612771806549
2015-01-01	80.4932827912291
2016-01-01	81.6565421712162
2017-01-01	84.3931407954266