Year	Percent
1966-01-01	15.2799000000000000
1967-01-01	14.8545000000000000
1968-01-01	15.4771000000000000
1969-01-01	15.8572000000000000
1970-01-01	12.1545000000000000
1971-01-01	11.9936000000000000
1972-01-01	12.4229000000000000
1973-01-01	14.4648000000000000
1974-01-01	15.7067000000000000
1975-01-01	14.1662000000000000
1976-01-01	15.3636000000000000
1977-01-01	10.4683000000000000
1978-01-01	9.7051400000000000
1979-01-01	8.6156399999999990
1980-01-01	9.2435200000000000
1981-01-01	9.3733100000000000
1982-01-01	7.9622800000000010
1983-01-01	6.8511399999999990
1984-01-01	6.3179600000000000
1985-01-01	6.9137800000000000
1986-01-01	8.4446900000000000
1987-01-01	7.4668399999999995
1988-01-01	5.4180100000000000
1989-01-01	4.6098200000000000
1990-01-01	5.6934700000000000
1991-01-01	5.9645000000000000
1992-01-01	8.0940300000000000
1993-01-01	8.2396800000000000
1994-01-01	10.4404000000000000
1995-01-01	10.7634000000000000
1996-01-01	11.2719000000000000
1997-01-01	11.9447000000000000
1998-01-01	12.6263000000000000
1999-01-01	13.6686000000000000
2000-01-01	13.7631000000000000
2001-01-01	14.8391000000000000
2002-01-01	15.6462000000000000
2003-01-01	17.1883000000000000
2004-01-01	16.5972000000000000
2005-01-01	16.8861000000000000
2006-01-01	16.9877000000000000
2007-01-01	17.0612000000000000
2008-01-01	17.2361000000000000
2009-01-01	16.8727000000000000
2010-01-01	18.0948000000000000
2011-01-01	16.4299000000000000
2012-01-01	13.5667000000000000
2013-01-01	14.2512000000000000
2014-01-01	14.7096000000000000
2015-01-01	15.0652000000000000
2016-01-01	15.9683000000000000