Year	Percent
1991	25.55325
1992	24.07793
1993	25.01413
1994	24.19831
1995	23.05709
1996	22.79082
1997	20.79606
1998	20.63493
1999	21.60238
2000	22.19917
2001	21.26238
2002	20.74523
2003	20.61047
2004	20.36216
2005	19.91096
2006	19.78171
2007	21.38956
2008	23.25007
2009	23.32357
2010	22.84823
2011	21.13499
2012	22.89203
2013	22.74488
2014	22.97458
2015	23.42141
2016	23.35319