Year	Percent
1991	26.184
1992	24.682
1993	24.964
1994	24.447
1995	26.012
1996	26.556
1997	24.818
1998	24.782
1999	25.085
2000	24.241
2001	24.631
2002	24.737
2003	25.078
2004	27.302
2005	26.713
2006	27.248
2007	26.836
2008	24.232
2009	23.969
2010	22.306
2011	22.77
2012	21.951
2013	21.752
2014	21.884
2015	22.158
2016	22.084
2017	22.184
2018	22.215
2019	22.333
2020	22.45
2021	22.696
2022	22.719