Year	Percent
1990	89.994
1991	90.436
1992	90.781
1993	90.879
1994	90.824
1995	90.868
1996	90.316
1997	89.73
1998	89.165
1999	88.59
2000	88.051
2001	87.225
2002	86.49
2003	85.887
2004	85.349
2005	84.935
2006	85.173
2007	85.46
2008	85.936
2009	86.284
2010	86.644
2011	86.909
2012	87.16
2013	87.405
2014	87.552
2015	87.612
2016	87.44
2017	87.393
2018	87.328
2019	87.254
2020	87.18
2021	87.1
2022	87.023
2023	86.957
2024	86.914
2025	86.898
2026	86.9
2027	86.928
2028	86.977
2029	87.035
2030	87.096