Year	Percent
1991	3.50399
1992	3.50782
1993	4.17169
1994	3.31092
1995	3.13141
1996	2.95986
1997	2.796
1998	2.63964
1999	2.49049
2000	2.34836
2001	2.21302
2002	2.08424
2003	1.9618
2004	1.84547
2005	1.73502
2006	1.63021
2007	1.53082
2008	1.4367
2009	1.34756
2010	1.26301
2011	1.18336
2012	1.10817
2013	1.24306
2014	1.11136
2015	1.02059
2016	1.01792
2017	1.00427
2018	0.95804
2019	0.91405