Year	Percent
1996-01-01	75.8325
1997-01-01	74.4203
1998-01-01	75.1361
1999-01-01	75.0675
2000-01-01	76.1437
2001-01-01	75.0467
2002-01-01	74.8461
2003-01-01	74.8762
2004-01-01	73.7604
2005-01-01	74.0979
2006-01-01	76.2430
2007-01-01	78.2597
2008-01-01	75.2544
2009-01-01	76.8277
2010-01-01	76.7107
2011-01-01	77.1699
2012-01-01	80.4412
2013-01-01	81.2271
2014-01-01	81.8874
2015-01-01	80.7851
2016-01-01	81.2045