Year	Percent
1962-01-01	3.4153599999999997
1963-01-01	3.5893599999999997
1964-01-01	4.0124699999999995
1965-01-01	4.5740500000000000
1966-01-01	5.1478000000000000
1967-01-01	5.3409100000000000
1968-01-01	5.3934900000000000
1969-01-01	5.4764900000000000
1970-01-01	5.6126900000000000
1971-01-01	5.1924000000000000
1972-01-01	5.0690500000000000
1973-01-01	4.4076300000000000
1974-01-01	3.6950400000000000
1975-01-01	5.7063400000000000
1976-01-01	6.5457400000000000
1977-01-01	8.1731900000000000
1978-01-01	8.1731900000000000
1979-01-01	10.4375000000000000
1980-01-01	12.2819000000000000
1981-01-01	12.3632000000000000
1982-01-01	10.4608000000000000
1983-01-01	9.7599000000000000
1984-01-01	10.8974000000000000
1985-01-01	11.2938000000000000
1986-01-01	11.2938000000000000
1987-01-01	11.2938000000000000
1988-01-01	9.1021200000000000
1989-01-01	9.1906900000000000
1990-01-01	7.7241899999999990
1991-01-01	6.8136600000000005
1992-01-01	6.7088199999999990
1993-01-01	5.3026100000000000
1994-01-01	4.8679900000000000
1995-01-01	4.5749600000000000
1996-01-01	4.2841500000000000
1997-01-01	4.9814600000000000
1998-01-01	6.1286500000000000
1999-01-01	6.5763300000000005
2000-01-01	7.7700000000000000
2001-01-01	8.9827200000000000
2002-01-01	8.5995500000000000
2003-01-01	8.8543800000000000
2004-01-01	8.3933600000000010
2005-01-01	8.8166700000000000
2006-01-01	10.0087000000000000
2007-01-01	10.2397000000000000
2008-01-01	10.7031000000000000
2009-01-01	11.7463000000000000
2010-01-01	14.1450000000000000
2011-01-01	16.9820000000000000
2012-01-01	19.3449000000000000
2013-01-01	21.3632000000000000