Year	Percent
1991	11.473
1992	11.417
1993	11.788
1994	12.422
1995	12.73
1996	12.288
1997	12.406
1998	11.678
1999	11.525
2000	11.265
2001	11.584
2002	11.701
2003	11.443
2004	12.13
2005	12.43
2006	12.785
2007	13.191
2008	13.198
2009	13.558
2010	15.059
2011	15.197
2012	15.406
2013	16.093
2014	16.659
2015	16.886
2016	16.861
2017	16.86
2018	16.756
2019	16.67
2020	16.623
2021	16.578
2022	16.53