Year	Percent
1990	79.827
1991	79.779
1992	79.778
1993	79.891
1994	79.531
1995	79.601
1996	79.486
1997	79.211
1998	78.978
1999	79.027
2000	78.796
2001	79.178
2002	79.708
2003	79.7
2004	79.714
2005	79.638
2006	79.412
2007	79.472
2008	79.564
2009	79.875
2010	80.217
2011	80.275
2012	80.223
2013	80.155
2014	80.133
2015	80.362
2016	80.274
2017	80.313
2018	80.413
2019	80.511
2020	80.545
2021	80.437
2022	80.293
2023	80.162
2024	80.088
2025	80.07
2026	80.017
2027	80.023
2028	80.086
2029	80.174
2030	80.246