Year	Percent
1991	10.685
1992	10.526
1993	10.706
1994	10.487
1995	10.444
1996	10.972
1997	11.592
1998	11.541
1999	11.421
2000	11.346
2001	9.692
2002	9.489
2003	7.233
2004	8.492
2005	7.452
2006	7.577
2007	7.532
2008	7.216
2009	6.616
2010	8.352
2011	8.42
2012	8.608
2013	8.244
2014	7.856
2015	7.468
2016	7.476
2017	7.326
2018	7.278
2019	7.255
2020	7.236
2021	7.215
2022	7.197