Year	Percent
1960	9.69324
1963	8.99469
1964	7.4538
1965	6.15305
1966	5.39347
1967	4.81218
1968	4.27988
1969	3.49048
1970	3.17199
1971	3.12566
1972	2.96418
1973	2.60054
1974	3.72033
1975	3.30312
1976	3.18333
1977	2.67786
1978	2.94313
1979	2.72314
1980	2.63437
1981	2.29824
1982	2.31446
1983	2.26549
1984	1.79829
1985	1.75906
1986	1.69383
1987	1.71149
1988	1.51672
1989	1.52444
1990	1.41845
1991	1.39158
1992	1.21281
1993	1.11396
1994	0.93019
1995	0.74659
1996	0.82861
1997	0.96707
1998	0.80741
1999	0.58073
2000	0.66011
2001	0.58779
2002	0.53362
2003	0.56316
2004	0.6266
2005	0.59497
2006	0.59082
2007	0.48057
2008	0.55394
2009	0.58837
2010	0.83552
2011	0.79221
2012	0.80382
2013	0.82645
2014	0.8464
2015	0.82699
2016	0.80566
2017	0.81868
2018	0.70792
2019	0.68232
2020	0.661
2021	0.66758
2022	0.66126