Year	Percent
1995	16.83902
1996	20.10767
1997	25.62997
1998	21.60661
1999	21.26235
2000	20.15083
2001	22.11252
2002	25.85353
2003	27.98534
2004	27.53406
2005	27.93848
2006	29.8077
2007	29.70296
2008	31.43428
2009	25.0388
2010	21.37694
2011	20.64001
2012	19.20023
2013	19.32122
2014	18.84284
2015	20.00916
2016	20.15353
2017	20.51919