Year	Percent
1960-01-01	5.4511600000000000
1961-01-01	5.1052599999999995
1962-01-01	5.2103800000000010
1963-01-01	5.7796300000000000
1964-01-01	5.7769000000000000
1965-01-01	7.2622100000000005
1966-01-01	6.5607899999999990
1967-01-01	6.7402399999999990
1968-01-01	8.2375000000000000
1969-01-01	9.6463800000000000
1970-01-01	11.0727000000000000
1971-01-01	15.2787000000000000
1972-01-01	18.7954000000000000
1973-01-01	20.2168000000000000
1974-01-01	22.1589000000000000
1975-01-01	23.8741000000000000
1976-01-01	25.1301000000000000
1977-01-01	26.4706000000000000
1978-01-01	28.4445000000000000
1979-01-01	27.0599000000000000
1980-01-01	27.4611000000000000
1981-01-01	28.6848000000000000
1982-01-01	30.1420000000000000
1983-01-01	30.1485000000000000
1984-01-01	26.4952000000000000
1985-01-01	24.7168000000000000
1986-01-01	26.4174000000000000
1987-01-01	27.5266000000000000
1988-01-01	25.1755000000000000
1989-01-01	25.7221000000000000
1990-01-01	23.8026000000000000
1991-01-01	14.7988000000000000
1992-01-01	15.6236000000000000
1993-01-01	17.2338000000000000
1994-01-01	17.6359000000000000
1995-01-01	17.8824000000000000
1996-01-01	18.8621000000000000
1997-01-01	20.4042000000000000
1998-01-01	20.9820000000000000
1999-01-01	23.3591000000000000
2000-01-01	25.5346000000000000
2001-01-01	29.1061000000000000
2002-01-01	29.8654000000000000
2003-01-01	27.7523000000000000
2004-01-01	22.5976000000000000
2005-01-01	17.3355000000000000
2006-01-01	16.8354000000000000
2007-01-01	17.2282000000000000
2008-01-01	18.7676000000000000
2009-01-01	19.4210000000000000
2010-01-01	19.8882000000000000
2011-01-01	21.0691000000000000
2012-01-01	20.8548000000000000
2013-01-01	21.2036000000000000
2014-01-01	22.7801000000000000
2015-01-01	24.1950000000000000
2016-01-01	25.1775000000000000