Year	Percent
1991	24.206
1992	26.143
1993	27.146
1994	24.644
1995	22.798
1996	21.632
1997	22.31
1998	22.562
1999	20.626
2000	21.775
2001	21.647
2002	18.423
2003	17.177
2004	20.282
2005	22.896
2006	25.659
2007	26.294
2008	26.494
2009	24.904
2010	23.153
2011	23.718
2012	22.157
2013	22.645
2014	23.376
2015	23.327
2016	22.389
2017	21.921
2018	21.333
2019	20.88
2020	20.645
2021	20.368
2022	20.08