Year	Percent
1991	7.702
1992	7.6
1993	7.777
1994	7.919
1995	7.623
1996	7.674
1997	6.841
1998	6.588
1999	6.323
2000	5.854
2001	5.543
2002	5.276
2003	5.175
2004	5.347
2005	5.436
2006	5.56
2007	5.71
2008	5.718
2009	5.993
2010	5.8
2011	5.653
2012	5.544
2013	5.484
2014	5.495
2015	5.373
2016	5.34
2017	5.374
2018	5.341
2019	5.237
2020	5.142
2021	5.049
2022	4.959
