Year	Percent
1991	23.313
1992	24.003
1993	23.553
1994	23.284
1995	23.255
1996	23.515
1997	23.215
1998	23.057
1999	23.638
2000	23.419
2001	23.472
2002	23.892
2003	24.146
2004	23.907
2005	24.091
2006	23.613
2007	23.369
2008	23.424
2009	23.23
2010	23.545
2011	24.198
2012	25.368
2013	26.028
2014	26.193
2015	26.107
2016	26.746
2017	26.13
2018	26.276
2019	26.39
2020	26.812
2021	27.228
2022	27.779