Year	Percent
1991	25.254
1992	24.366
1993	23.957
1994	23.309
1995	23.206
1996	23.185
1997	22.542
1998	22.253
1999	22.518
2000	22.427
2001	24.213
2002	28.772
2003	23.664
2004	23.4
2005	23.989
2006	26.652
2007	27.077
2008	26.511
2009	26.823
2010	26.086
2011	25.772
2012	24.507
2013	24.207
2014	23.761
2015	24.204
2016	24.534
2017	24.543
2018	24.492
2019	24.437
2020	24.381
2021	24.321
2022	24.26