Year	Percent
1986-01-01	93.5139185380637
1987-01-01	92.9055621177946
1988-01-01	90.4499348129361
1989-01-01	88.4477688469719
1990-01-01	86.9968212466059
1991-01-01	84.7222148111768
1992-01-01	84.2896801293250
1993-01-01	84.5098484912021
1994-01-01	85.2842182253332
1995-01-01	86.9128653074125
1996-01-01	87.0339050171788
1997-01-01	86.7328402545856
1998-01-01	85.3300123597886
1999-01-01	85.4628261226158
2000-01-01	86.9606160959729
2001-01-01	87.1418201532191
2002-01-01	87.6227659538248
2003-01-01	87.7881225350970
2004-01-01	89.0553557284901
2005-01-01	89.9649876772142
2006-01-01	90.0163589665047
2007-01-01	90.0539065949067
2008-01-01	89.3445919392481
2009-01-01	87.4015534058903
2010-01-01	87.7216111534620
2011-01-01	87.9111267968702
2012-01-01	86.9166926380144
2013-01-01	88.2540577951216
2014-01-01	89.2103588040218
2015-01-01	88.8843963132653
2016-01-01	89.7577983009734
2017-01-01	90.4332601340035