Year	Percent
1995	24.81063
1996	25.43789
1997	25.70742
1998	25.32738
1999	24.85864
2000	24.44988
2001	24.13253
2002	23.48216
2003	22.61344
2004	22.21654
2005	21.36737
2006	21.14638
2007	21.15224
2008	20.43693
2009	19.85065
2010	19.90772
2011	19.3295
2012	19.09918
2013	18.88218
2014	18.93092
2015	19.53332
2016	19.35285
2017	19.41316