Year	Percent
1999-01-01	39.2692027333425
2000-01-01	39.4710396740264
2001-01-01	40.0755603144088
2002-01-01	40.8190011893709
2003-01-01	41.2487289735479
2004-01-01	40.5705048391321
2005-01-01	41.4699980522962
2006-01-01	42.4842470989913
2007-01-01	43.2568141096832
2008-01-01	44.2752646675461
2009-01-01	44.7693196581879
2010-01-01	44.8359393604283
2011-01-01	45.0917301921570
2012-01-01	45.5832017342000
2013-01-01	45.6656741295143