Year	Percent
1991	10.576
1992	10.101
1993	10.021
1994	9.757
1995	9.488
1996	11.235
1997	10.289
1998	9.685
1999	9.123
2000	8.841
2001	5.906
2002	7.373
2003	9.206
2004	8.088
2005	8.532
2006	7.513
2007	5.459
2008	5.394
2009	5.817
2010	6.273
2011	4.988
2012	4.234
2013	3.45
2014	2.775
2015	2.708
2016	2.524
2017	2.441
2018	2.331
2019	2.239
2020	2.144
2021	2.065
2022	1.997