Year	%
1990	28.57
1992	28.63
1995	30.57
1998	27.97
2000	23.61
2002	25.61
2003	22.83
2004	23.63
2005	7.44
2006	19.99
2008	18.08
2009	19.41
2010	15.63
2011	14.47
2012	13.06
2013	3.12
2015	2.91
2016	9.46