Year	Percent
1991	23.789
1992	24.489
1993	24.084
1994	23.102
1995	24.404
1996	23.453
1997	23.861
1998	23.984
1999	23.503
2000	23.264
2001	21.708
2002	22.967
2003	23.664
2004	23.848
2005	24.026
2006	25.237
2007	25.333
2008	24.687
2009	24.548
2010	24.422
2011	24.425
2012	24.515
2013	24.573
2014	23.967
2015	23.864
2016	23.409
2017	23.444
2018	23.507
2019	23.544
2020	23.518
2021	23.473
2022	23.356