Year	%
1990	28.94
1992	28.97
1993	44.7
1995	32.11
1996	23.32
1997	22.87
1998	27.36
1999	23.21
2000	29.72
2001	20.55
2002	26.37
2003	24.11
2004	17.76
2005	19.88
2006	15.85
2007	17.15
2008	19.22
2009	15.91
2010	14.83
2011	15.98
2012	13.9
2013	12.93
2014	13.9
2015	12.1
2016	11.91
2017	12.33