Year	Percent
1991	7.792
1992	7.296
1993	6.777
1994	6.578
1995	6.496
1996	6.257
1997	6.02
1998	5.968
1999	5.763
2000	5.549
2001	5.284
2002	4.956
2003	4.9
2004	4.714
2005	4.572
2006	4.47
2007	4.34
2008	4.254
2009	4.105
2010	3.923
2011	3.712
2012	3.538
2013	3.383
2014	3.276
2015	3.224
2016	3.045
2017	3.022
2018	2.925
2019	2.862
2020	2.832
2021	2.774
2022	2.718