Year	Percent
1990	90.471
1991	90.383
1992	90.276
1993	90.26
1994	90.375
1995	90.244
1996	90.128
1997	90.155
1998	90.072
1999	90.166
2000	89.99
2001	89.958
2002	89.892
2003	89.928
2004	89.911
2005	89.81
2006	89.755
2007	89.932
2008	89.925
2009	89.862
2010	89.749
2011	89.888
2012	89.985
2013	90.064
2014	90.035
2015	90.089
2016	90.249
2017	90.242
2018	90.227
2019	90.202
2020	90.165
2021	90.117
2022	90.058
2023	89.992
2024	89.922
2025	89.852
2026	89.781
2027	89.711
2028	89.642
2029	89.572
2030	89.502