Year	Percent
1991	9.062
1992	9.048
1993	9.059
1994	8.629
1995	9.04
1996	9.255
1997	9.6
1998	10.035
1999	10.594
2000	11.331
2001	11.731
2002	12.097
2003	12.493
2004	13.333
2005	13.653
2006	14.7
2007	17.787
2008	19.631
2009	22.486
2010	25.266
2011	28.005
2012	30.686
2013	33.151
2014	31.902
2015	32.827
2016	33.25
2017	33.694
2018	34.242
2019	34.76
2020	35.212
2021	35.69
2022	36.236