Year	Percent
1976	17.5998
1977	17.18532
1978	17.72545
1979	17.20102
1980	14.35492
1981	11.07534
1982	10.32645
1983	13.82284
1984	16.98989
1985	16.57316
1986	8.85244
1987	8.88849
1988	11.21235
1989	11.24459
1990	15.32739
1991	13.04328
1992	11.05983
1993	10.79256
1994	10.39583
1995	10.47494
1996	27.7347
1997	20.11698
1998	20.10639
1999	23.28889
2000	75.4732
2001	83.79143
2002	77.8664
2003	88.88356
2004	74.01003
2005	78.30134
2006	84.36734
2007	90.62556
2008	101.39259
2009	107.99435
2010	93.79878
2011	95.7691
2012	99.3308
2013	90.81339
2014	88.01506