Year	Percent
1972	52.49608
1973	54.33349
1974	57.6445
1975	63.34669
1976	70.02174
1977	73.04141
1978	75.79994
1979	74.84151
1980	72.9539
1981	78.0477
1982	77.25316
1983	79.73157
1984	85.00558
1985	101.00999
1986	81.57376
1987	82.73832
1988	83.42189
1989	86.22504
1990	84.57995
1991	81.97585
1992	85.22523
1993	84.81398
1994	83.43105
1995	84.03849
1996	86.54222
1997	85.35892
1999	83.62003
2000	79.98582
2001	86.21335
2002	88.06338
2003	90.07537
2004	91.1589
2005	93.55741
2006	84.72257
2007	93.77551
2008	118.83029
2009	91.05117
2010	95.80919
2011	97.91376
2012	101.72996
2013	106.11718
2014	107.82734
2015	105.53533
2016	105.51898