Year	Percent
1990	90.056
1991	90.046
1992	88.129
1993	85.747
1994	81.183
1995	81.962
1996	82.55
1997	81.737
1998	81.211
1999	81.1
2000	82.495
2001	83.794
2002	83.528
2003	84.265
2004	84.105
2005	82.032
2006	81.18
2007	80.628
2008	82.118
2009	80.794
2010	80.926
2011	80.453
2012	80.386
2013	80.604
2014	80.469
2015	80.816
2016	81.484
2017	81.475
2018	81.481
2019	81.504
2020	81.547
2021	81.607
2022	81.689
2023	81.789
2024	81.901
2025	82.017
2026	82.136
2027	82.26
2028	82.381
2029	82.486
2030	82.563