Year	Percent
1991	24.746
1992	25.749
1993	26.882
1994	26.675
1995	27.871
1996	30.013
1997	29.968
1998	27.919
1999	25.547
2000	24.279
2001	22.891
2002	21.725
2003	21.007
2004	21.819
2005	21.574
2006	22.561
2007	22.378
2008	21.62
2009	22.096
2010	20.831
2011	17.459
2012	14.877
2013	12.438
2014	15.307
2015	15.634
2016	21.991
2017	23.016
2018	24.451
2019	24.65
2020	24.098
2021	23.37
2022	22.433