Year	Percent
1984	6.17886
1985	7.04225
1986	6.93128
1987	10.18908
1988	13.50085
2000	13.41566
2001	13.54361
2002	29.04042
2003	27.77152
2004	31.75424
2005	34.05809
2006	30.06954
2007	32.31224
2008	31.68199
2009	33.93847
2010	27.46249
2011	28.0678
2012	32.50426
2013	30.64732
2014	29.80135
2015	31.55676
2016	29.00763
2017	29.04168