Year	Percent
1991	13.882
1992	13.738
1993	13.181
1994	13.457
1995	13.189
1996	12.523
1997	12.737
1998	12.522
1999	12.9
2000	13.287
2001	12.571
2002	11.778
2003	11.982
2004	11.957
2005	11.98
2006	11.6
2007	11.123
2008	10.448
2009	9.902
2010	9.913
2011	9.948
2012	10.063
2013	10.126
2014	10.159
2015	10.027
2016	9.991
2017	9.884
2018	9.8
2019	9.789
2020	9.709
2021	9.557
2022	9.397