Year	Percent
1991	10.856
1992	10.095
1993	7.243
1994	8.107
1995	7.941
1996	6.712
1997	6.598
1998	6.763
1999	6.926
2000	6.379
2001	6.658
2002	6.57
2003	6.073
2004	6.543
2005	5.791
2006	5.193
2007	5.461
2008	6.138
2009	4.024
2010	4.785
2011	4.223
2012	3.934
2013	4.29
2014	4.24
2015	4.398
2016	4.677
2017	4.608
2018	4.477
2019	4.348
2020	4.238
2021	4.129
2022	4.046