Year	Percent
1961	11.0496
1962	11.05842
1963	11.07166
1964	11.08489
1965	11.09371
1966	11.10253
1967	11.11577
1968	11.13782
1969	11.15988
1970	11.18193
1971	11.20399
1972	11.22604
1973	11.2481
1974	11.27015
1975	11.27015
1976	11.29221
1977	11.30544
1978	11.31426
1979	11.31426
1980	11.33632
1981	11.35837
1982	11.3672
1983	11.38043
1984	11.40248
1985	11.42454
1986	11.44659
1987	11.44659
1988	11.44659
1989	11.44659
1990	11.451
1991	11.45983
1992	11.46865
1993	11.46865
1994	11.46865
1995	11.38043
1996	11.38043
1997	11.33632
1998	11.33632
1999	11.29221
2000	11.29221
2001	11.27015
2002	11.27015
2003	11.27015
2004	11.27015
2005	11.27015
2006	11.28603
2007	11.31426
2008	11.33632
2009	11.85991
2010	12.54009
2011	13.0725
2012	13.62387
2013	13.86383
2014	14.22509
2015	14.31376
2016	14.41168
2017	14.69796
2018	14.81838
2019	14.92248
2020	14.95115
2021	14.95247