Year	Percent
1991-01-01	31.00001335
1992-01-01	20.95344162
1993-01-01	12.76964664
1994-01-01	11.85705566
1995-01-01	14.35548401
1996-01-01	16.10880280
1997-01-01	17.74244118
1998-01-01	18.59673119
1999-01-01	18.32002640
2000-01-01	17.27201462
2001-01-01	16.50417709
2002-01-01	17.85857582
2003-01-01	17.65831184
2004-01-01	18.63179588
2005-01-01	21.72720909
2006-01-01	24.18872643
2007-01-01	26.39192009
2008-01-01	26.84229851
2009-01-01	31.37491035
2010-01-01	32.30987167
2011-01-01	32.00904083
2012-01-01	31.69627762
2013-01-01	31.80625343