Year	Percent
1991	11.115
1992	10.964
1993	12.177
1994	14.634
1995	14.205
1996	13.308
1997	16.403
1998	16.073
1999	15.445
2000	13.087
2001	13.938
2002	12.982
2003	11.038
2004	13.081
2005	12.672
2006	13.339
2007	13.263
2008	11.309
2009	12.866
2010	14.049
2011	13.455
2012	12.818
2013	13.61
2014	16.029
2015	13.491
2016	10.695
2017	10.977
2018	10.793
2019	10.729
2020	10.681
2021	10.673
2022	10.66