Year	Percent
1991	77.049
1992	74.592
1993	72.116
1994	71.433
1995	71.166
1996	70.807
1997	71.516
1998	73.222
1999	74.909
2000	73.985
2001	74.663
2002	75.3
2003	75.429
2004	75.184
2005	81.275
2006	80.957
2007	81.364
2008	80.206
2009	81.096
2010	80.21
2011	79.588
2012	79.988
2013	79.93
2014	78.974
2015	76.5
2016	76.328
2017	76.318
2018	76.298
2019	76.257
2020	76.214
2021	76.172
2022	76.13