Year	Percent
1990-01-01	24.653000000000002
1991-01-01	24.367500000000000
1992-01-01	23.079200000000000
1993-01-01	26.331600000000000
1994-01-01	31.471200000000000
1995-01-01	33.720900000000000
1996-01-01	35.901800000000000
1997-01-01	35.159100000000000
1998-01-01	32.085200000000000
1999-01-01	30.414600000000000
2000-01-01	28.975500000000000
2001-01-01	27.795100000000000
2002-01-01	27.854700000000000
2003-01-01	27.591500000000000
2004-01-01	28.249600000000000
2005-01-01	29.583000000000002
2006-01-01	30.990500000000000
2007-01-01	32.028900000000000
2008-01-01	31.668800000000000
2009-01-01	43.255900000000000
2010-01-01	55.356800000000000
2011-01-01	58.633000000000000