Year	Percent
1999-01-01	49.4201022636826
2000-01-01	50.0856771108578
2001-01-01	51.2313927767411
2002-01-01	50.6541601324403
2003-01-01	50.1900294746965
2004-01-01	52.5572312515706
2005-01-01	52.6792716037792
2006-01-01	53.2293548405932
2007-01-01	54.4455323486299
2008-01-01	53.9416876397919
2009-01-01	52.6470861780979
2010-01-01	51.5994160566038
2011-01-01	49.8644999668228
2012-01-01	49.1395788813158
2013-01-01	48.5185501782099
2014-01-01	48.8859560753006