Year	Percent
1991	24.616
1992	24.695
1993	24.62
1994	24.647
1995	24.367
1996	24.181
1997	24.172
1998	24.093
1999	24.008
2000	23.783
2001	23.492
2002	23.646
2003	23.783
2004	23.904
2005	23.993
2006	24.134
2007	23.762
2008	23.447
2009	23.238
2010	22.959
2011	22.594
2012	21.614
2013	21.563
2014	21.51
2015	21.411
2016	21.381
2017	21.417
2018	21.396
2019	21.344
2020	21.269
2021	21.217
2022	21.14