Year	Percent
1991	23.483
1992	24.309
1993	22.649
1994	23.425
1995	24.347
1996	24.687
1997	25.665
1998	25.484
1999	25.755
2000	24.231
2001	22.381
2002	20.487
2003	16.694
2004	14.914
2005	15.009
2006	14.811
2007	15.142
2008	14.96
2009	18.044
2010	21.171
2011	25.235
2012	26.364
2013	26.741
2014	26.138
2015	26.23
2016	25.963
2017	24.749
2018	24.547
2019	24.541
2020	24.499
2021	24.568
2022	24.603