Year	Percent
1990	82.138
1991	81.908
1992	81.779
1993	81.492
1994	81.075
1995	80.701
1996	80.283
1997	79.889
1998	79.314
1999	78.588
2000	80.528
2001	82.575
2002	84.574
2003	86.456
2004	88.169
2005	88.162
2006	88.227
2007	88.284
2008	88.332
2009	88.369
2010	88.4
2011	88.495
2012	88.574
2013	88.702
2014	88.805
2015	88.887
2016	88.919
2017	89.114
2018	89.292
2019	89.453
2020	89.596
2021	89.725
2022	89.842
2023	89.95
2024	90.052
2025	90.152
2026	90.249
2027	90.344
2028	90.443
2029	90.555
2030	90.685