Year	Percent
1965	32.73183
1966	31.85079
1967	31.1333
1968	31.50579
1969	30.72351
1970	31.36392
1971	31.00413
1972	31.96497
1973	30.79283
1974	29.53977
1975	29.11971
1976	27.61011
1977	33.64508
1978	31.35335
1979	30.8236
1980	28.67678
1981	27.17658
1982	27.00575
1983	23.19328
1984	21.97183
1985	20.59053
1986	21.62963
1987	23.98644
1988	23.94243
1989	25.50676
1990	23.99487
1991	24.25903
1992	26.57967
1993	18.23673
1994	19.60975
1995	19.14485
1996	18.32232
1997	18.96789
1998	19.001
1999	18.97879
2000	18.11774
2001	18.62096
2002	18.27168
2003	17.47378
2004	17.56095
2005	16.73418
2006	15.62508
2007	15.85753
2008	16.00119
2009	16.38719
2010	17.26971
2011	16.69739
2012	16.65724
2013	16.72366
2014	16.82584
2015	17.20942
2016	17.19266
2017	16.69294
2018	16.4988
2019	16.80228
2020	17.49687
2021	16.9661
2022	16.9799