Year	Percent
1990	80.861
1991	81.286
1992	81.541
1993	81.934
1994	82.347
1995	82.496
1996	82.321
1997	82.018
1998	81.775
1999	81.494
2000	81.135
2001	80.763
2002	80.524
2003	80.565
2004	80.361
2005	80.416
2006	80.401
2007	80.395
2008	80.43
2009	80.279
2010	80.664
2011	80.836
2012	81.11
2013	81.426
2014	81.968
2015	82.253
2016	82.582
2017	82.834
2018	82.971
2019	82.943
2020	82.723
2021	82.316
2022	81.723
2023	81.017
2024	80.302
2025	79.647
2026	79.034
2027	78.468
2028	77.982
2029	77.627
2030	77.437