Year	Percent
1991	8.473
1992	8.856
1993	8.943
1994	8.789
1995	8.776
1996	8.683
1997	8.659
1998	8.374
1999	8.243
2000	7.935
2001	8.087
2002	8.102
2003	7.572
2004	7.384
2005	7.513
2006	7.618
2007	7.624
2008	7.456
2009	7.534
2010	5.958
2011	5.806
2012	5.953
2013	5.965
2014	5.592
2015	5.388
2016	5.408
2017	5.425
2018	5.425
2019	5.422
2020	5.418
2021	5.415
2022	5.413