Year	Percent
1991	7.665
1992	7.611
1993	7.479
1994	7.302
1995	6.555
1996	6.412
1997	5.588
1998	5.702
1999	6.698
2000	5.837
2001	6.041
2002	5.694
2003	5.452
2004	5.171
2005	4.999
2006	5.199
2007	4.933
2008	4.845
2009	4.368
2010	4.388
2011	4.625
2012	4.475
2013	4.234
2014	3.939
2015	3.961
2016	4.359
2017	4.478
2018	4.377
2019	4.28
2020	4.198
2021	4.123
2022	4.055