Year	Percent
1960-01-01	5.6747300000000000
1961-01-01	6.2486100000000000
1962-01-01	6.7126399999999995
1963-01-01	6.1731500000000000
1964-01-01	6.7101899999999990
1965-01-01	7.4526000000000000
1966-01-01	8.1767500000000000
1967-01-01	9.2037100000000010
1968-01-01	9.9478000000000000
1969-01-01	7.8160500000000000
1970-01-01	5.8209900000000000
1971-01-01	6.4711500000000000
1972-01-01	6.7659300000000000
1973-01-01	6.9071399999999990
1974-01-01	6.1529800000000000
1975-01-01	9.6172000000000000
1976-01-01	11.9237000000000000
1977-01-01	13.8500000000000000
1978-01-01	14.0682000000000000
1979-01-01	13.9147000000000000
1980-01-01	16.1797000000000000
1981-01-01	19.9157000000000000
1982-01-01	20.2669000000000000
1983-01-01	21.8038000000000000
1984-01-01	23.9161000000000000
1985-01-01	21.8998000000000000
1986-01-01	22.5364000000000000
1987-01-01	17.1998000000000000
1988-01-01	17.7255000000000000
1989-01-01	13.6706000000000000
1990-01-01	6.4925700000000000
1991-01-01	7.4386800000000010
1992-01-01	7.8628399999999990
1993-01-01	9.2166300000000000
1994-01-01	8.5255100000000000
1995-01-01	6.6979300000000000
1996-01-01	6.0652300000000010
1997-01-01	6.5068400000000000
1998-01-01	6.9834200000000000
1999-01-01	8.2347000000000000
2000-01-01	9.1345800000000000
2001-01-01	10.8624000000000000
2002-01-01	9.6350500000000000
2003-01-01	9.4446200000000000
2004-01-01	8.5723899999999990
2005-01-01	8.7088000000000000
2006-01-01	8.7539100000000010
2007-01-01	12.0969000000000000
2008-01-01	16.8660000000000000
2009-01-01	19.4024000000000000
2010-01-01	17.5239000000000000
2011-01-01	16.9103000000000000
2012-01-01	17.4128000000000000
2013-01-01	17.9533000000000000
2014-01-01	17.9116000000000000
2015-01-01	17.6923000000000000
2016-01-01	17.2662000000000000