Year	Percent
1992	82.03245
1993	82.13764
1994	82.10209
1995	80.44838
1996	79.81391
1997	79.89473
1998	79.76064
1999	79.66637
2000	79.78416
2001	79.44794
2002	79.07134
2003	78.89817
2004	78.7756
2005	78.63318
2006	78.4815
2007	78.31818
2008	78.10179
2009	78.07656
2010	80.43923
2011	80.37504
2012	80.38378
2013	80.37712
2014	80.305
2015	80.10509
2016	80.09857
2017	80.08805
2018	80.02226
2019	79.25855
2020	79.26925
2021	79.19247