Year	Percent
1990	81.908
1991	81.081
1992	79.273
1993	77.282
1994	76.192
1995	76.822
1996	77.076
1997	76.321
1998	75.578
1999	76.439
2000	75.767
2001	75.856
2002	75.94
2003	75.926
2004	75.425
2005	76.893
2006	76.364
2007	76.891
2008	76.989
2009	76.353
2010	76.109
2011	77.131
2012	77.689
2013	78.672
2014	79.321
2015	80.017
2016	80.327
2017	80.588
2018	80.785
2019	80.957
2020	81.13
2021	81.276
2022	81.409
2023	81.541
2024	81.684
2025	81.844
2026	81.997
2027	82.168
2028	82.354
2029	82.548
2030	82.743