Year	Percent
1990	82.668
1991	82.501
1992	82.258
1993	81.985
1994	81.557
1995	81.086
1996	80.719
1997	80.397
1998	80.118
1999	79.873
2000	79.622
2001	79.149
2002	78.596
2003	78.528
2004	78.206
2005	78.004
2006	77.679
2007	77.207
2008	76.84
2009	76.397
2010	75.957
2011	75.514
2012	75.207
2013	74.969
2014	74.823
2015	74.715
2016	74.629
2017	74.584
2018	74.547
2019	74.507
2020	74.463
2021	74.417
2022	74.373
2023	74.312
2024	74.217
2025	74.077
2026	73.904
2027	73.693
2028	73.453
2029	73.203
2030	72.957