Year	Percent
1990-01-01	21.773700000000000
1991-01-01	22.969100000000000
1992-01-01	23.599300000000000
1993-01-01	23.752800000000000
1994-01-01	26.670800000000000
1995-01-01	28.860800000000000
1996-01-01	28.424900000000000
1997-01-01	29.701999999999998
1998-01-01	33.123300000000000
1999-01-01	36.986400000000000
2000-01-01	43.182700000000000
2001-01-01	48.965400000000000
2002-01-01	53.808400000000000
2003-01-01	59.315600000000000
2004-01-01	63.319700000000000
2005-01-01	64.928600000000000
2006-01-01	68.223800000000000
2007-01-01	73.192000000000000
2008-01-01	70.589800000000000
2009-01-01	74.277500000000000
2010-01-01	76.877200000000000
2011-01-01	71.795400000000000