Year	Percent
1979-01-01	60.7564135833333
1980-01-01	61.2941675250000
1981-01-01	61.1357863583333
1982-01-01	60.7811595250000
1983-01-01	60.4370241750000
1984-01-01	60.5500798666667
1985-01-01	60.8037821333333
1986-01-01	61.8863103750000
1987-01-01	61.9580831250000
1988-01-01	62.3789828500000
1989-01-01	63.1579828666667
1990-01-01	63.7460075750000
1991-01-01	63.1387184666667
1992-01-01	62.8633873000000
1993-01-01	62.4502895916667
1994-01-01	62.9334411083333
1995-01-01	63.5410478083333
1996-01-01	63.5200923250000
1997-01-01	63.1234503666667
1998-01-01	62.9973447666667
1999-01-01	62.7632763333333
2000-01-01	63.1374280333333
2001-01-01	63.2976961333333
2002-01-01	63.3634238500000
2003-01-01	63.5865176083333
2004-01-01	63.4588724583333
2005-01-01	64.3970819833333
2006-01-01	64.7550899416667
2007-01-01	65.1748854416667
2008-01-01	65.4807299750000
2009-01-01	65.4317799500000
2010-01-01	65.3897517000000
2011-01-01	65.4226062333333
2012-01-01	65.1556485083333
2013-01-01	64.9455519666667
2014-01-01	64.7136228666667
2015-01-01	65.0083743333333
2016-01-01	64.8795585083333
2017-01-01	65.1693286166667