Year	Percent
2000	80.64617
2001	80.67125
2002	80.69756
2003	80.7254
2004	80.75478
2005	80.78702
2006	80.83575
2007	80.88607
2008	80.93867
2009	80.99285
2010	81.04895
2011	81.10697
2012	81.1669
2013	81.22875
2014	81.29214
2015	81.35313
2016	81.41597
2017	81.43568
2018	81.52109
2019	81.61224
2020	81.70875