Year	%
1997	9.94
2002	9.19
2003	10.5
2004	12.08
2005	12.48
2006	10.91
2007	15.37
2008	15.1
2009	15.46
2010	17.18
2011	18.6
2012	17.77
2013	18.04
2014	18.84
2015	19.42
2016	21.41