Year	Percent
1965	18.76438
1966	21.12672
1967	21.85706
1968	16.90325
1969	19.53678
1970	16.31204
1971	18.49472
1972	18.97019
1973	15.92595
1974	19.47164
1975	18.59711
1976	18.58866
1977	17.48063
1978	14.06929
1979	13.08537
1980	15.07753
1981	16.60812
1982	14.80852
1983	9.92392
1984	13.43657
1985	20.72656
1986	16.13588
1987	13.12383
1988	14.82531
1989	13.39882
1990	14.83205
1991	13.54691
1992	6.75157
1993	13.73791
1994	17.08008
1995	13.46597
1996	19.34262
1997	16.69573
1998	18.89032
1999	15.48127
2000	15.66706
2001	15.62707
2002	12.56837
2003	14.79336
2004	18.0638
2005	17.14824
2006	19.23012
2007	21.19769
2008	19.02107
2009	10.74255
2010	9.60986
2011	8.66587
2012	8.04452
2013	7.14448
2014	8.7453
2015	8.28425
2016	7.87399
2017	8.34097
2018	7.31938
2019	9.81926
2020	8.77286
2021	8.8499
2022	7.19192