Year	Percent
1991	22.083
1992	22.231
1993	21.961
1994	23.73
1995	23.313
1996	22.975
1997	21.949
1998	21.912
1999	22.668
2000	23.428
2001	23.61
2002	23.301
2003	24.068
2004	23.854
2005	23.701
2006	23.559
2007	23.187
2008	23.474
2009	24.511
2010	23.919
2011	23.907
2012	23.973
2013	24.352
2014	25.578
2015	25.599
2016	25.703
2017	25.595
2018	25.277
2019	25.698
2020	25.839
2021	26.046
2022	26.235