Year	Percent
1990-01-01	23.624900000000000
1991-01-01	25.017800000000000
1992-01-01	24.630300000000000
1993-01-01	24.532700000000000
1994-01-01	27.448000000000000
1995-01-01	29.053100000000000
1996-01-01	29.018800000000000
1997-01-01	30.579300000000000
1998-01-01	32.551700000000000
1999-01-01	34.242700000000000
2000-01-01	36.664400000000000
2001-01-01	38.401400000000000
2002-01-01	39.670100000000000
2003-01-01	40.138100000000000
2004-01-01	36.785800000000000
2005-01-01	31.881999999999998
2006-01-01	29.451400000000000
2007-01-01	30.820200000000000
2008-01-01	28.988300000000000
2009-01-01	31.056500000000000
2010-01-01	34.641000000000000
2011-01-01	33.809000000000000