Year	Percent
1990	72.96
1991	73.111
1992	73.169
1993	73.17
1994	73.169
1995	73.124
1996	73.258
1997	73.318
1998	73.476
1999	73.916
2000	73.907
2001	73.859
2002	73.733
2003	73.606
2004	73.32
2005	73.042
2006	72.783
2007	71.881
2008	70.847
2009	68.663
2010	67.955
2011	68.938
2012	69.816
2013	70.508
2014	70.477
2015	70.388
2016	72.069
2017	72.095
2018	72.124
2019	72.145
2020	72.152
2021	72.164
2022	72.166
2023	72.153
2024	72.121
2025	72.065
2026	72.003
2027	71.919
2028	71.813
2029	71.681
2030	71.527