Year	Percent
1976	5.10632
1977	4.41014
1978	4.41461
1979	4.28893
1980	4.3264
1981	3.96693
1982	3.64604
1983	3.41221
1984	3.58235
1985	3.13516
1986	3.22696
1987	3.19749
1988	3.04846
1989	3.01155
1990	3.09712
1991	2.81128
1992	2.45333
1993	2.20444
1994	2.37155
1995	2.1586
1996	1.98247
1997	1.90548
1998	1.79334
1999	1.72222
2000	1.6473
2001	1.6707
2002	1.56277
2003	1.49193
2004	1.47647
2005	1.2594
2006	1.30319
2007	1.41639
2008	1.34222
2009	1.14682
2010	1.26733
2011	1.40191
2012	1.34855
2013	1.25472
2014	1.20074
2015	1.12979
2016	1.11032
2017	1.21054
2018	1.1306
2019	1.05242
2020	1.06808
2021	1.21863
2022	1.3858