Year	Percent
1976-01-01	31.768100000000000
1977-01-01	26.019400000000000
1978-01-01	25.371100000000000
1979-01-01	25.236100000000000
1980-01-01	22.491000000000000
1981-01-01	22.491000000000000
1982-01-01	30.030700000000000
1983-01-01	29.963400000000000
1984-01-01	28.197700000000000
1985-01-01	28.518800000000000
1986-01-01	26.440600000000000
1987-01-01	25.043600000000000
1988-01-01	27.497400000000000
1989-01-01	29.649000000000000
1990-01-01	30.648800000000000
1991-01-01	33.802800000000000
1992-01-01	34.030800000000000
1993-01-01	33.887700000000000
1994-01-01	34.181500000000000
1995-01-01	33.828700000000000
1996-01-01	35.665300000000000
1997-01-01	38.947800000000000
1998-01-01	42.055000000000000
1999-01-01	42.748000000000005
2000-01-01	39.705300000000000
2001-01-01	41.656300000000000
2002-01-01	44.678100000000000
2003-01-01	47.820600000000000
2004-01-01	50.721700000000000
2005-01-01	52.373200000000000
2006-01-01	52.330700000000000
2007-01-01	56.087900000000000
2008-01-01	61.171200000000000
2009-01-01	65.369400000000000
2010-01-01	64.725700000000000
2011-01-01	60.379000000000000
2012-01-01	56.054400000000000
2013-01-01	55.573700000000000
2014-01-01	54.679100000000000
2015-01-01	55.959600000000000
2016-01-01	57.543700000000000