Year	Percent
1991	35.637
1992	36.533
1993	32.041
1994	32.929
1995	33.852
1996	35.663
1997	35.727
1998	33.906
1999	33.593
2000	33.051
2001	33.028
2002	32.433
2003	31.727
2004	30.931
2005	28.386
2006	31.821
2007	29.148
2008	27.34
2009	25.494
2010	24.43
2011	23.919
2012	26.221
2013	24.888
2014	24.353
2015	23.82
2016	25.177
2017	25.392
2018	25.33
2019	25.16
2020	24.964
2021	24.775
2022	24.412