Year	Percent
1991	14.627
1992	13.801
1993	12.394
1994	14.299
1995	15.347
1996	14.973
1997	17.843
1998	17.232
1999	15.995
2000	16.489
2001	15.255
2002	15.214
2003	15.966
2004	15.919
2005	14.118
2006	13.198
2007	12.475
2008	12.472
2009	12.549
2010	12.6
2011	12.137
2012	11.614
2013	12.166
2014	12.513
2015	12.058
2016	11.761
2017	11.771
2018	11.73
2019	11.699
2020	11.677
2021	11.654
2022	11.649