Year	Percent
1990	14.97341
1991	15.32615
1992	15.32754
1993	16.05488
1994	16.21229
2000	16.57475
2001	15.64729
2002	20.93614
2003	21.68949
2004	21.43824
2005	20.81534
2006	21.11867
2007	22.12243
2008	22.45222
2009	22.15476
2010	22.14155
2011	20.26535
2012	21.71292
2013	19.76624
2014	20.41116