Year	Percent
1991	15.14266
1992	15.12278
1993	14.92892
1994	15.61605
1995	16.67821
1996	13.439
1997	11.42036
1998	13.8543
1999	13.16565
2010	13.89199
2011	14.74166
2012	13.68091
2013	12.18157