Year	Percent
1971	168.03873
1972	162.17893
1973	167.68726
1974	170.46718
1975	166.46687
1976	133.85212
1977	97.45897
1978	96.17937
1979	111.7045
1980	93.45646
1981	69.10214
1982	52.01227
1983	41.04083
1984	25.65547
1985	19.51719
1986	17.6556
1987	14.52868
1988	7.00156
1989	10.53343
1990	13.66562
1991	11.38901
1992	12.92988
1993	25.50764
1994	26.4385
1995	29.75577
1996	27.84213
1997	33.30579
1998	26.29626
1999	34.1716
2000	31.10742
2001	26.7062
2002	31.62621
2003	42.41603
2004	41.7455
2005	42.32243
2006	49.93743
2007	52.8642
2008	63.84412
2009	84.11385
2010	79.84883
2011	68.45432
2012	47.77337
2013	59.66341
2014	66.08839
2015	64.433
2016	57.30112