Year	Percent
1970	48.43802
1971	50.68309
1972	53.92666
1973	55.62358
1975	60.63903
1976	62.82024
1977	67.24558
1978	68.52681
1979	89.45355
1980	86.04085
1981	84.51025
2004	87.79198
2005	88.50575
2014	99.49517
2015	101.48953
2016	101.99707