Year	Percent
1976	19.94048
1977	17.25469
1978	15.61202
1979	16.02094
1980	10.50937
1981	12.31267
1982	13.04904
1983	11.47849
1984	12.08914
1985	12.7753
1986	12.74112
1987	12.14185
1988	10.94725
1989	10.40151
1990	10.88742
1991	9.9689
1992	10.01265
1993	9.15099
1994	8.66609
1995	9.19812
1996	9.06308
1997	8.30904
1998	8.12766
1999	4.99635
2000	5.70501
2001	6.148
2002	5.19142
2003	5.17745
2004	5.27618
2005	4.97794
2006	4.90645
2007	4.37599
2008	4.07488
2009	3.88064
2010	3.64174
2011	3.70365
2012	3.65727
2013	3.33059
2014	3.19195
2015	3.07196
2016	3.09727
2017	2.99475
2018	2.56386
2019	2.70724
2020	3.14186
2021	3.28024
2022	3.55176