Year	Percent
1976	9.62185
1977	9.16464
1978	8.40619
1979	7.29619
1980	6.38232
1981	7.30014
1982	5.9714
1983	7.22967
1984	6.0215
1985	5.36883
1986	5.61307
1987	4.94183
1988	4.41682
1989	4.00831
1990	4.48913
1991	4.45966
1992	3.57214
1993	3.8964
1994	3.85622
1995	3.8957
1996	3.63648
1997	3.25934
1998	2.45518
1999	2.89437
2000	2.641
2001	2.63784
2002	2.69362
2003	2.46145
2004	3.2271
2005	3.03801
2006	2.78226
2007	2.6279
2008	2.53632
2009	2.24086
2010	2.23477
2011	2.19278
2012	1.99899
2013	2.71154
2014	2.33076
2015	2.30967
2016	2.28193
2017	2.82652
2018	2.68476
2019	2.71032
2020	2.7069
2021	2.88365
2022	2.8671