Year	Percent
1996	5.4385
1997	12.04145
1998	15.32706
1999	14.27651
2000	11.78741
2001	18.34038
2002	23.07456
2003	17.94515
2004	16.07998
2005	12.53831
2006	21.06051
2007	18.47469
2008	10.11176
2009	16.85968
2010	16.41669
2011	18.75465
2012	15.02325
2013	18.56197
2014	17.28989
2015	20.58394
2016	15.8514