Year	Percent
1991	76.512
1992	76.622
1993	76.193
1994	75.639
1995	74.897
1996	74.117
1997	72.982
1998	73.024
1999	72.913
2000	75.13
2001	77.412
2002	79.889
2003	82.231
2004	84.414
2005	84.371
2006	84.364
2007	84.392
2008	84.484
2009	84.271
2010	84.221
2011	84.292
2012	84.404
2013	84.661
2014	84.832
2015	84.957
2016	85.024
2017	85.238
2018	85.426
2019	85.609
2020	85.774
2021	85.923
2022	86.059