Year	Percent
1975	11.50668
1976	8.7922
1977	9.22992
1978	8.24629
1979	8.14359
1980	7.47544
1981	5.751
1982	5.21145
1983	5.45455
1984	5.13843
1985	4.86772
1986	4.70286
1987	5.00583
1988	4.74218
1989	3.72243
1990	3.44453
1991	3.45719
1992	3.43638
1993	3.21928
1994	2.44049
1995	3.20251
1996	3.33403
1997	2.67264
1998	1.99435
1999	2.33451
2000	1.99542
2001	2.11819
2002	1.88959
2003	1.9785
2004	1.6432
2005	1.5866
2006	1.45348
2007	1.30937
2008	1.18907
2009	1.40858
2010	1.32527
2011	1.19835
2012	1.40989
2013	1.5964
2014	1.58998
2015	1.49873
2016	1.5062
2017	1.51133
2018	1.67898
2019	1.59237
2020	1.93192
2021	1.67476
2022	1.4544