Year	Percent
1991	13.73
1992	13.423
1993	13.165
1994	12.924
1995	12.58
1996	12.318
1997	11.959
1998	11.684
1999	11.344
2000	11.126
2001	10.913
2002	10.788
2003	10.623
2004	10.439
2005	10.262
2006	10.086
2007	10.009
2008	9.918
2009	10.052
2010	10.355
2011	10.311
2012	10.308
2013	10.273
2014	10.254
2015	10.132
2016	10.082
2017	10.032
2018	10.029
2019	9.993
2020	9.954
2021	9.893
2022	9.827