Year	Percent
1990	72.467
1991	72.164
1992	71.824
1993	71.556
1994	71.422
1995	71.153
1996	70.969
1997	70.946
1998	70.891
1999	71.007
2000	70.943
2001	71.087
2002	71.194
2003	71.387
2004	71.567
2005	71.712
2006	71.856
2007	72.206
2008	72.422
2009	72.566
2010	72.617
2011	73.001
2012	73.235
2013	73.351
2014	73.303
2015	73.256
2016	73.245
2017	73.163
2018	73.065
2019	72.948
2020	72.815
2021	72.688
2022	72.554
2023	72.425
2024	72.311
2025	72.222
2026	72.164
2027	72.127
2028	72.117
2029	72.139
2030	72.197