Year	Percent
2005-01-01	80.7370412817982
2006-01-01	81.2663500894158
2007-01-01	80.8326083300553
2008-01-01	80.1551541176881
2009-01-01	78.0739957813410
2010-01-01	77.8416139244055
2011-01-01	77.9218547261867
2012-01-01	78.5123080198610
2013-01-01	78.2521026869494
2014-01-01	78.1052326176966
2015-01-01	78.3404707985333
2016-01-01	78.5693260256402
2017-01-01	78.9532844787314