Year	Percent
1990	86.35
1991	86.383
1992	86.414
1993	86.46
1994	86.417
1995	86.394
1996	86.397
1997	86.384
1998	86.339
1999	86.365
2000	86.351
2001	86.351
2002	86.685
2003	87.865
2004	88.935
2005	89.145
2006	89.319
2007	90.728
2008	91.814
2009	89.396
2010	89.681
2011	89.854
2012	88.911
2013	89.249
2014	89.866
2015	90.427
2016	90.392
2017	90.512
2018	90.634
2019	90.761
2020	90.894
2021	91.033
2022	91.176
2023	91.323
2024	91.47
2025	91.616
2026	91.764
2027	91.91
2028	92.054
2029	92.196
2030	92.335
