Year	Percent
1990	83.854
1991	83.724
1992	83.392
1993	83.167
1994	83.242
1995	83.297
1996	81.887
1997	81.299
1998	81.505
1999	80.625
2000	79.853
2001	79.06
2002	78.227
2003	79.713
2004	78.833
2005	79.036
2006	79.21
2007	79.964
2008	79.646
2009	79.34
2010	79.059
2011	79.259
2012	79.462
2013	78.935
2014	78.725
2015	78.543
2016	78.444
2017	78.754
2018	79.087
2019	79.404
2020	79.678
2021	79.952
2022	80.194
2023	80.402
2024	80.584
2025	80.743
2026	80.904
2027	81.045
2028	81.165
2029	81.265
2030	81.343