Year	Percent
1990	77.443
1991	78.282
1992	77.627
1993	78.006
1994	77.239
1995	76.02
1996	76.126
1997	75.343
1998	75.565
1999	75.36
2000	76.425
2001	75.767
2002	76.694
2003	75.088
2004	75.288
2005	75.791
2006	75.274
2007	74.302
2008	74.08
2009	76.236
2010	75.632
2011	74.569
2012	75.406
2013	75.701
2014	76.426
2015	75.756
2016	74.562
2017	74.481
2018	74.423
2019	74.394
2020	74.394
2021	74.318
2022	74.269
2023	74.25
2024	74.256
2025	74.287
2026	74.262
2027	74.245
2028	74.253
2029	74.304
2030	74.406