Year	Percent
1990	77.552
1991	77.733
1992	77.725
1993	77.597
1994	77.543
1995	77.779
1996	77.936
1997	78.07
1998	78.219
1999	78.302
2000	78.244
2001	78.275
2002	78.13
2003	77.853
2004	77.533
2005	77.239
2006	77.041
2007	76.829
2008	76.589
2009	76.279
2010	75.87
2011	75.638
2012	75.323
2013	74.95
2014	74.561
2015	74.176
2016	73.946
2017	73.892
2018	73.848
2019	73.804
2020	73.754
2021	73.694
2022	73.631
2023	73.567
2024	73.506
2025	73.451
2026	73.393
2027	73.341
2028	73.292
2029	73.243
2030	73.193