Year	Percent
1990	83.544
1991	83.754
1992	84.154
1993	84.635
1994	84.757
1995	84.574
1996	84.169
1997	83.684
1998	82.975
1999	82.34
2000	80.831
2001	85.151
2002	85.639
2003	85.993
2004	86.025
2005	86.673
2006	87.342
2007	87.964
2008	88.537
2009	88.93
2010	89.306
2011	89.128
2012	88.95
2013	88.774
2014	88.63
2015	88.504
2016	88.396
2017	88.668
2018	88.935
2019	89.169
2020	89.353
2021	89.499
2022	89.605
2023	89.683
2024	89.75
2025	89.817
2026	89.887
2027	89.958
2028	90.028
2029	90.09
2030	90.141