Year	Percent
1990	75.373
1991	75.663
1992	75.757
1993	75.628
1994	75.286
1995	74.821
1996	74.627
1997	74.365
1998	73.933
1999	73.533
2000	73.297
2001	73.596
2002	74.005
2003	74.478
2004	74.962
2005	75.153
2006	75.398
2007	75.683
2008	75.471
2009	75.268
2010	75.008
2011	74.796
2012	74.7
2013	74.82
2014	74.637
2015	74.333
2016	74.183
2017	74.159
2018	74.138
2019	74.108
2020	74.088
2021	74.145
2022	74.203
2023	74.266
2024	74.355
2025	74.475
2026	74.694
2027	74.938
2028	75.188
2029	75.418
2030	75.626