Year	Percent
1997-01-01	18.93498993
1998-01-01	16.39105606
1999-01-01	14.92498875
2000-01-01	11.58978558
2001-01-01	10.84651375
2002-01-01	12.35283375
2003-01-01	13.79998684
2004-01-01	15.50069618
2005-01-01	18.47007561
2006-01-01	22.55744743
2007-01-01	29.27222633
2008-01-01	35.58543015
2009-01-01	45.60973358
2010-01-01	49.03129578
2011-01-01	50.40460968
2012-01-01	50.46179962
2013-01-01	47.97636032