Year	Percent
1990	79.544
1991	79.649
1992	79.7
1993	79.974
1994	79.931
1995	79.965
1996	80.156
1997	80.244
1998	80.269
1999	80.341
2000	80.394
2001	80.454
2002	80.476
2003	80.375
2004	80.028
2005	79.743
2006	79.772
2007	79.678
2008	79.506
2009	79.265
2010	78.88
2011	78.765
2012	78.487
2013	78.2
2014	77.855
2015	77.532
2016	77.43
2017	77.354
2018	77.286
2019	77.228
2020	77.184
2021	77.152
2022	77.128
2023	77.113
2024	77.105
2025	77.104
2026	77.11
2027	77.121
2028	77.135
2029	77.154
2030	77.177