Year	Percent
1991	8.674
1992	8.438
1993	8.676
1994	8.515
1995	8.355
1996	7.836
1997	7.506
1998	7.122
1999	7.11
2000	6.702
2001	6.823
2002	5.26
2003	5.013
2004	4.701
2005	4.567
2006	4.549
2007	4.889
2008	4.936
2009	4.627
2010	4.896
2011	4.832
2012	4.924
2013	5.08
2014	6.006
2015	6.971
2016	6.934
2017	7.192
2018	7.296
2019	7.138
2020	6.928
2021	6.758
2022	6.615