Year	Percent
1990	72.714
1991	72.92
1992	73.052
1993	73.099
1994	73.047
1995	72.881
1996	72.539
1997	72.129
1998	71.675
1999	71.208
2000	70.757
2001	70.586
2002	70.469
2003	70.417
2004	70.452
2005	70.582
2006	70.841
2007	71.171
2008	71.465
2009	72.009
2010	76.437
2011	75.638
2012	75.308
2013	75.416
2014	75.725
2015	75.076
2016	75.326
2017	75.693
2018	75.999
2019	76.238
2020	76.406
2021	76.522
2022	76.563
2023	76.553
2024	76.531
2025	76.527
2026	76.562
2027	76.62
2028	76.709
2029	76.833
2030	76.996