Year	Percent
1960-01-01	7.5956300000000000
1961-01-01	7.8272300000000000
1962-01-01	9.2418300000000000
1963-01-01	9.9401900000000000
1964-01-01	10.8851000000000000
1965-01-01	10.0914000000000000
1966-01-01	9.1169600000000000
1967-01-01	9.0698100000000000
1968-01-01	9.2183200000000000
1969-01-01	10.1316000000000000
1970-01-01	3.3583600000000000
1971-01-01	3.7348199999999996
1972-01-01	3.9243500000000000
1973-01-01	4.3859500000000000
1974-01-01	5.2270900000000005
1975-01-01	12.7907000000000000
1976-01-01	14.9565000000000000
1977-01-01	13.9121000000000000
1978-01-01	14.8033000000000000
1979-01-01	16.5615000000000000
1980-01-01	19.5902000000000000
1981-01-01	26.2590000000000000
1982-01-01	28.0614000000000000
1983-01-01	31.0584000000000000
1984-01-01	26.8275000000000000
1985-01-01	26.2795000000000000
1986-01-01	28.2923000000000000
1987-01-01	25.8030000000000000
1988-01-01	25.5190000000000020
1989-01-01	23.6953000000000000
1990-01-01	19.2549000000000000
1991-01-01	15.3838000000000000
1992-01-01	13.4675000000000000
1993-01-01	10.6981000000000000
1994-01-01	9.0025800000000000
1995-01-01	7.2061000000000000
1996-01-01	7.5467800000000000
1997-01-01	6.5056600000000000
1998-01-01	5.9347800000000000
1999-01-01	7.9142500000000000
2000-01-01	9.7675900000000000
2001-01-01	9.7319500000000000
2002-01-01	9.6959500000000000
2003-01-01	11.3643000000000000
2004-01-01	12.5798000000000000
2005-01-01	13.7140000000000000
2006-01-01	14.7841000000000000
2007-01-01	16.2257000000000000
2008-01-01	18.2135000000000000
2009-01-01	19.6167000000000000
2010-01-01	21.0241000000000000
2011-01-01	21.6202000000000000
2012-01-01	21.6353000000000000
2013-01-01	21.6169000000000000
2014-01-01	22.1010000000000000
2015-01-01	21.9558000000000000
2016-01-01	21.2313000000000000