Year	Percent
1973-01-01	63.023320000000000
1974-01-01	60.792190000000005
1975-01-01	59.758630000000004
1976-01-01	62.089030000000010
1977-01-01	67.557319999999990
1978-01-01	69.804020000000000
1979-01-01	68.223180000000000
1980-01-01	57.831450000000000
1981-01-01	56.218250000000000
1982-01-01	63.108810000000000
1983-01-01	63.529219999999995
1984-01-01	64.438970000000000
1985-01-01	65.300820000000000
1986-01-01	66.685380000000010
1987-01-01	66.824609999999990
1988-01-01	66.775990000000010
1989-01-01	63.166290000000004
1990-01-01	99.446180000000000
1991-01-01	98.531740000000000
1992-01-01	93.980400000000000
1993-01-01	90.331050000000000
1994-01-01	88.951990000000010
1995-01-01	84.095180000000000
1996-01-01	91.390790000000000
1997-01-01	97.417590000000000
1998-01-01	90.884520000000000
1999-01-01	84.725670000000000
2000-01-01	82.422840000000010
2001-01-01	90.674770000000000
2002-01-01	97.059419999999990
2003-01-01	99.540450000000000
2004-01-01	99.999280000000000
2005-01-01	99.999280000000000
2006-01-01	99.999980000000010
2007-01-01	99.998970000000000
2008-01-01	99.998650000000000
2009-01-01	99.998980000000000
2010-01-01	99.999530000000010