Year	Percent
1991	25.128
1992	24.691
1993	26.402
1994	28.853
1995	28.673
1996	28.702
1997	27.146
1998	26.46
1999	24.6
2000	25.82
2001	25.403
2002	26.355
2003	25.518
2004	23.809
2005	23.352
2006	22.317
2007	21.861
2008	21.333
2009	20.219
2010	19.101
2011	20.532
2012	21.165
2013	19.201
2014	22.74
2015	20.915
2016	20.072
2017	20.115
2018	20.085
2019	19.825
2020	19.625
2021	19.352
2022	19.09