Year	Percent
1960-01-01	1.7411911116721800
1961-01-01	1.8708496140632200
1962-01-01	2.7526680521471800
1963-01-01	2.9216403937175400
1964-01-01	3.6567366387360900
1965-01-01	3.6664770856961400
1966-01-01	3.4323676480588100
1967-01-01	2.9875460669516200
1968-01-01	3.2428261799152500
1969-01-01	2.6480696142054600
1970-01-01	4.1406536880828900
1971-01-01	5.0163221128192100
1972-01-01	5.9062535172410200
1973-01-01	7.9155430450917300
1974-01-01	14.6648478944192000
1975-01-01	12.2270629206872000
1976-01-01	9.7114211093591300
1977-01-01	9.7674647360703400
1978-01-01	7.5737122394973100
1979-01-01	8.4653349041487800
1980-01-01	13.5400697127800000
1981-01-01	11.5097558377123000
1982-01-01	9.5849276467744300
1983-01-01	8.6692715980851500
1984-01-01	7.0676563832817400
1985-01-01	5.1956219542943400
1986-01-01	2.5385259178141600
1987-01-01	3.1594076405343100
1988-01-01	2.7008152750811100
1989-01-01	3.7654804828339200
1990-01-01	3.4483121796180900
1991-01-01	4.0470318274485300
1992-01-01	5.0569800569800500
1993-01-01	4.5690708846465500
1994-01-01	4.1299218163825700
1995-01-01	4.2228161409948600
1996-01-01	2.9789248648126700
1997-01-01	2.1092456273948000
1998-01-01	2.2277073265431500
1999-01-01	1.6634599500771400
2000-01-01	2.8530303928715600
2001-01-01	2.7851654271355500
2002-01-01	2.4653231917116400
2003-01-01	2.0984721914692200
2004-01-01	2.2256791642889200
2005-01-01	2.4876966516408600
2006-01-01	2.6663149457707200
2007-01-01	2.4539652813873900
2008-01-01	4.0756607636822100
2009-01-01	0.3740799757186240
2010-01-01	1.5255160211824800
2011-01-01	3.2897537489822800
2012-01-01	2.4856735286006800
2013-01-01	1.3749062031015700
2014-01-01	0.2410474298267730
2015-01-01	0.0375143805125363
2016-01-01	0.1833348611238480
2017-01-01	1.3814587140721000