Year	Percent
1980	4.80661
1981	4.87147
1982	5.02124
1983	4.95514
1984	4.94612
1985	4.90293
1986	4.72537
1987	4.48145
1988	4.28201
1989	4.2066
1990	3.84114
1991	3.23072
1992	3.06937
1993	2.89164
1994	2.90037
1995	2.88912
1996	2.55393
1997	2.47007
1998	2.31134
1999	2.13019
2000	1.94286
2001	1.94494
2002	1.89968
2003	1.85863
2004	1.82775
2005	1.25377
2006	1.36222
2007	1.57842
2008	1.56747
2009	1.43668
2010	1.64941
2011	1.67048
2012	1.54715
2013	1.46654
2014	1.4433
2015	1.44956
2016	1.39874
2017	1.44354
2018	1.39279
2019	1.39212
2020	1.32935
2021	1.28809
2022	1.46497