Year	Percent
1966	6.68924
1967	5.75494
1968	5.40425
1969	5.62153
1970	4.60433
1971	4.55788
1972	4.78583
1973	5.27624
1974	5.15635
1975	4.41429
1976	4.29709
1977	4.66358
1978	4.70902
1979	3.97338
1980	4.07448
1981	4.32951
1982	4.65249
1983	4.03127
1984	4.65338
1985	4.21937
1986	3.87731
1987	3.45151
1988	3.16196
1989	3.50121
1990	3.28737
1991	3.02972
1992	2.79178
1993	2.69213
1994	2.60095
1995	2.8519
1996	2.7927
1997	2.63712
1998	2.1446
1999	1.94099
2000	2.15185
2001	2.33951
2002	1.78112
2003	1.61079
2004	1.62253
2005	1.14564
2006	1.16519
2007	1.17442
2008	0.85779
2009	0.83359
2010	1.20191
2011	1.31213
2012	1.65473
2013	1.30213
2014	1.38246
2015	0.95758
2016	0.96116
2017	1.3048
2018	1.02657
2019	1.26629
2020	1.3819
2021	1.08899
2022	1.17289