Year	Percent
1990	82.911
1991	82.159
1992	81.028
1993	80.978
1994	81.107
1995	78.964
1996	80.255
1997	80.978
1998	82.132
1999	82.333
2000	81.147
2001	81.082
2002	81.06
2003	81.053
2004	81.029
2005	80.974
2006	81
2007	80.964
2008	80.861
2009	80.707
2010	80.589
2011	80.355
2012	80.33
2013	80.909
2014	80.348
2015	79.658
2016	79.011
2017	78.913
2018	78.771
2019	78.594
2020	78.394
2021	78.269
2022	78.129
2023	77.984
2024	77.854
2025	77.757
2026	77.784
2027	77.848
2028	77.933
2029	78.015
2030	78.083