Year	Percent
1990	79.858
1991	80.398
1992	80.392
1993	80.39
1994	80.392
1995	80.458
1996	80.442
1997	79.515
1998	79.402
1999	79.424
2000	78.758
2001	78.407
2002	78.465
2003	77.709
2004	77.705
2005	78.429
2006	78.274
2007	78.179
2008	78.159
2009	78.447
2010	78.568
2011	78.583
2012	79.367
2013	80.416
2014	81.245
2015	81.489
2016	82.372
2017	82.541
2018	82.633
2019	82.641
2020	82.562
2021	82.379
2022	82.098
2023	81.763
2024	81.447
2025	81.191
2026	80.976
2027	80.827
2028	80.721
2029	80.61
2030	80.468