Year	Percent
1965	12.90416
1966	10.27876
1967	9.98039
1968	9.72128
1969	9.18581
1970	9.63756
1971	10.86588
1972	10.98487
1973	11.95252
1974	10.23084
1975	6.58391
1976	8.15217
1977	8.08714
1978	7.50443
1979	7.79628
1980	6.35351
1981	6.47552
1982	9.59616
1983	8.65832
1984	8.34598
1985	7.63431
1986	7.8004
1987	8.09436
1988	8.97787
1989	9.61607
1990	8.12368
1991	6.71649
1992	5.99079
1993	5.13683
1994	5.08267
1995	5.35146
1996	5.61087
1997	5.22197
1998	5.25272
1999	4.45783
2000	4.67991
2001	4.56859
2002	10.20665
2003	10.32817
2004	8.36249
2005	7.93875
2006	6.93557
2007	7.45235
2008	7.31895
2009	5.27362
2010	7.13217
2011	6.99873
2012	5.78174
2013	6.05292
2014	6.7127
2015	5.15669
2016	6.26457
2017	5.23162
2018	4.53788
2019	5.31856
2020	6.35703
2021	7.30631
2022	6.6399