Year	Percent
1991	6.992
1992	7.103
1993	7.387
1994	7.157
1995	7.198
1996	7.064
1997	7.87
1998	9.641
1999	10.83
2000	14.177
2001	13.242
2002	12.102
2003	11.505
2004	10.628
2005	9.207
2006	9.094
2007	8.357
2008	7.653
2009	6.593
2010	5.867
2011	6.084
2012	6.057
2013	6.162
2014	6.094
2015	6.44
2016	6.562
2017	6.489
2018	6.509
2019	6.489
2020	6.452
2021	6.406
2022	6.347