Year	Percent
1991	27.282
1992	28.426
1993	28.422
1994	27.264
1995	25.954
1996	25.338
1997	24.439
1998	24.537
1999	24.048
2000	22.683
2001	24.036
2002	23.861
2003	23.499
2004	23.36
2005	22.864
2006	23.305
2007	23.847
2008	22.565
2009	23.162
2010	24.314
2011	24.931
2012	25.858
2013	27.048
2014	26.22
2015	26.062
2016	25.898
2017	25.974
2018	25.958
2019	26.026
2020	26.055
2021	26.067
2022	26.078