Year	Percent
1991	6.33
1992	5.994
1993	5.907
1994	5.804
1995	5.622
1996	5.516
1997	4.28
1998	3.651
1999	3.608
2000	2.951
2001	2.641
2002	2.786
2003	3.059
2004	3.263
2005	3.624
2006	3.477
2007	2.729
2008	1.797
2009	1.785
2010	1.703
2011	1.544
2012	1.544
2013	1.585
2014	1.537
2015	1.43
2016	1.411
2017	1.463
2018	1.442
2019	1.419
2020	1.399
2021	1.364
2022	1.328