Year	Percent
1960-01-01	4.5694800000000000
1961-01-01	4.9139400000000000
1962-01-01	6.0507900000000000
1963-01-01	6.5395800000000000
1964-01-01	7.2878600000000000
1965-01-01	7.8928899999999995
1966-01-01	8.5481300000000000
1967-01-01	10.1714000000000000
1968-01-01	8.8819100000000010
1969-01-01	4.9175800000000000
1970-01-01	3.2929600000000000
1971-01-01	4.2115000000000000
1972-01-01	5.1253699999999990
1973-01-01	5.4902100000000000
1974-01-01	4.1779699999999990
1975-01-01	5.4147600000000000
1976-01-01	6.2826400000000000
1977-01-01	7.5232100000000010
1978-01-01	9.4378900000000000
1979-01-01	9.8059200000000000
1980-01-01	10.3095000000000000
1981-01-01	13.9983000000000000
1982-01-01	16.2539000000000000
1983-01-01	16.9965000000000000
1984-01-01	16.9204000000000000
1985-01-01	15.0275000000000000
1986-01-01	17.4964000000000000
1987-01-01	13.7702000000000000
1988-01-01	12.8403000000000000
1989-01-01	10.1284000000000000
1990-01-01	4.5805400000000000
1991-01-01	4.5538500000000000
1992-01-01	5.7358100000000000
1993-01-01	7.0815600000000005
1994-01-01	6.4282600000000000
1995-01-01	6.2718000000000000
1996-01-01	6.2946100000000000
1997-01-01	6.9471600000000000
1998-01-01	7.4258000000000000
1999-01-01	7.7983199999999995
2000-01-01	7.5244700000000000
2001-01-01	8.8611399999999990
2002-01-01	7.9104000000000000
2003-01-01	7.9566800000000000
2004-01-01	7.7520899999999990
2005-01-01	8.1489000000000000
2006-01-01	7.9035000000000000
2007-01-01	11.5235000000000000
2008-01-01	17.2330000000000000
2009-01-01	20.1609000000000000
2010-01-01	16.6373000000000000
2011-01-01	13.0548000000000000
2012-01-01	11.5409999999999990
2013-01-01	11.5748000000000000
2014-01-01	12.8957000000000000
2015-01-01	14.0441000000000000
2016-01-01	14.6597000000000000