Year	%
1990	25.87
1992	26.02
1993	28.41
1995	21.21
1996	35.63
1997	17.15
1998	18.83
1999	18.34
2000	18.89
2001	16.64
2002	20.87
2003	16.68
2004	12.43
2005	12.84
2006	11.69
2007	11.74
2008	12.66
2009	11.5
2010	11.69
2011	11.79
2012	9.81
2013	10.42
2014	10.04
2015	10.13
2016	10.45
2017	11.15