Year	Percent
1990	82.228
1991	81.514
1992	81.093
1993	80.732
1994	80.498
1995	80.331
1996	80.221
1997	80.148
1998	81.18
1999	81.913
2000	82.411
2001	82.736
2002	82.926
2003	83.008
2004	82.88
2005	82.635
2006	82.27
2007	81.733
2008	80.997
2009	80.036
2010	78.816
2011	77.311
2012	75.492
2013	75.307
2014	75.064
2015	74.776
2016	74.552
2017	74.61
2018	74.67
2019	74.735
2020	74.805
2021	74.882
2022	74.962
2023	75.043
2024	75.126
2025	75.21
2026	75.296
2027	75.382
2028	75.468
2029	75.552
2030	75.635