Year	Percent
1991	13.683
1992	13.497
1993	13.489
1994	13.673
1995	13.531
1996	13.462
1997	12.577
1998	12.618
1999	12.54
2000	12.197
2001	12.171
2002	12.278
2003	12.256
2004	12.016
2005	11.877
2006	11.688
2007	11.633
2008	11.415
2009	11.421
2010	11.381
2011	11.542
2012	11.097
2013	11.193
2014	11.187
2015	11.046
2016	11.081
2017	11.094
2018	11.074
2019	11.058
2020	11.042
2021	11.028
2022	11.015