Year	Percent
1990	90.951
1991	90.974
1992	91.041
1993	91.12
1994	91.157
1995	91.18
1996	90.334
1997	89.355
1998	88.247
1999	87.028
2000	88.644
2001	87.762
2002	86.869
2003	86.6
2004	86.466
2005	86.295
2006	86.17
2007	86.058
2008	85.952
2009	85.847
2010	86.282
2011	87.171
2012	87.783
2013	88.604
2014	87.247
2015	87.812
2016	87.848
2017	87.894
2018	87.928
2019	87.942
2020	87.929
2021	87.893
2022	87.83
2023	87.744
2024	87.646
2025	87.543
2026	87.438
2027	87.33
2028	87.22
2029	87.114
2030	87.016