Year	Percent
1990	83.62
1991	84.18
1992	84.119
1993	84.247
1994	83.639
1995	82.977
1996	84.259
1997	84.584
1998	84.524
1999	83.485
2000	81.892
2001	82.311
2002	82.68
2003	83.31
2004	83.822
2005	84.133
2006	83.311
2007	82.165
2008	81.25
2009	80.565
2010	79.861
2011	79.187
2012	78.501
2013	77.788
2014	77.045
2015	76.276
2016	76.266
2017	76.223
2018	76.169
2019	76.104
2020	76.033
2021	75.984
2022	75.933
2023	75.871
2024	75.796
2025	75.712
2026	75.643
2027	75.567
2028	75.481
2029	75.392
2030	75.307