Year	Percent
1990	83.603
1991	83.538
1992	83.557
1993	83.535
1994	83.339
1995	83.047
1996	82.035
1997	81.985
1998	81.91
1999	81.862
2000	81.82
2001	81.665
2002	81.383
2003	81.276
2004	80.737
2005	81.481
2006	81.162
2007	80.243
2008	79.559
2009	79.892
2010	79.758
2011	80.348
2012	80.851
2013	81.921
2014	81.561
2015	81.431
2016	82.061
2017	82.206
2018	82.357
2019	82.518
2020	82.695
2021	82.882
2022	83.077
2023	83.272
2024	83.457
2025	83.626
2026	83.78
2027	83.922
2028	84.043
2029	84.123
2030	84.147