Year	Percent
1990	86.444
1991	86.144
1992	85.825
1993	85.489
1994	85.135
1995	84.768
1996	84.392
1997	84.002
1998	83.609
1999	83.23
2000	82.874
2001	82.547
2002	82.832
2003	82.57
2004	83.208
2005	83.094
2006	82.972
2007	82.75
2008	82.829
2009	82.888
2010	82.207
2011	81.509
2012	81.032
2013	81.035
2014	80.769
2015	80.674
2016	80.383
2017	80.381
2018	80.388
2019	80.396
2020	80.4
2021	80.408
2022	80.414
2023	80.415
2024	80.404
2025	80.378
2026	80.345
2027	80.296
2028	80.233
2029	80.166
2030	80.096