Year	Percent
1990	1.63
1991	3.41
1992	7.4
1993	10.87
1994	11.34
1995	13.94
1996	15.77
1997	18.67
1998	14.87
1999	22.06
2000	21.14
2001	24
2002	20.24
2003	26.85
2004	25.66
2005	15.15
2006	12.12
2007	10.1
2008	12.02
2009	27.39
2010	32.92
2011	22.37
2012	20.86
2013	18.68
2014	14.96
2015	13.09
2016	13.4
2017	12.1
2018	11.84
2019	11.06
2020	17.87