Year	Percent
1991	23.358
1992	23.695
1993	24.015
1994	23.784
1995	23.631
1996	23.64
1997	23.63
1998	23.77
1999	23.662
2000	24.252
2001	24.625
2002	24.806
2003	24.337
2004	24.156
2005	24.017
2006	23.368
2007	22.467
2008	22.162
2009	22.565
2010	22.59
2011	21.833
2012	20.976
2013	20.751
2014	21.038
2015	20.903
2016	20.919
2017	20.555
2018	20.603
2019	20.529
2020	20.401
2021	20.237
2022	20.063