Year	Percent
1990-01-01	40.17830000000000
1991-01-01	42.12500000000000
1992-01-01	42.83500000000000
1993-01-01	43.04680000000000
1994-01-01	45.53280000000000
1995-01-01	47.68600000000001
1996-01-01	47.75820000000000
1997-01-01	45.94680000000000
1998-01-01	46.99060000000000
1999-01-01	45.76890000000000
2000-01-01	41.91430000000000
2001-01-01	40.18180000000000
2002-01-01	41.99960000000000
2003-01-01	46.19930000000000
2004-01-01	47.48640000000000
2005-01-01	43.71860000000000
2006-01-01	40.07440000000000
2007-01-01	39.29490000000000
2008-01-01	40.89870000000000
2009-01-01	46.81870000000000
2010-01-01	48.55840000000000
2011-01-01	47.94240000000000