Year	%
1990	25.87
1992	26.02
1993	28.37
1995	21.21
1996	35.63
1997	17.15
1998	18.83
1999	18.34
2000	18.89
2001	16.61
2002	20.85
2003	16.68
2004	12.43
2005	9.57
2006	9.75
2007	9.22
2008	10.5
2009	8.92
2010	10.72
2011	11.11
2012	7.22
2013	7.48
2014	6
2015	6
2016	6.19
2017	6.66