Year	Percent
1991	12.098
1992	10.271
1993	9.699
1994	10.146
1995	10.054
1996	10.576
1997	11.934
1998	10.412
1999	9.932
2000	10.448
2001	10.571
2002	10.673
2003	11.543
2004	11.848
2005	12.198
2006	12.542
2007	10.931
2008	10.89
2009	10.261
2010	10.932
2011	11.436
2012	8.738
2013	10.214
2014	11.663
2015	13.884
2016	13.652
2017	13.802
2018	13.784
2019	13.728
2020	13.658
2021	13.622
2022	13.514