Year	Percent
1970	73.97881
1971	74.69324
1975	81.91291
1976	81.67279
1996	95.35022
1997	94.29742
1998	101.89649
1999	98.84431
2000	98.90572
2001	98.64281
2002	102.64082
2003	100.36038
2004	98.93506
2005	97.01966
2006	99.25808
2007	101.9599
2008	104.98545
2009	104.7266
2010	104.31629
2011	104.1188
2012	102.79186
2013	100.32931
2014	101.20665
2015	100.88934