Year	Percent
1980	107.39727
1981	103.22333
1982	92.75925
1983	76.55638
1984	80.79295
1985	80.95177
1986	102.54553
1987	95.39247
1988	92.8366
1989	93.47001
1990	80.16033
1991	78.40034
1992	76.09487
1993	79.72718
1994	74.79419
1995	76.72839
1996	78.26954
1997	75.34157
1998	75.26406
1999	74.47064
2000	73.42667
2001	76.85837
2002	75.6147
2003	65.74315
2004	63.91276
2005	64.00302
2006	69.31908
2007	73.69545
2008	88.14387
2009	91.55181
2010	85.05012
2011	88.63562
2012	89.46334
2013	96.31768
2014	102.43568
2015	99.9569
2016	96.62866
2017	80.26383