Year	Measure
1971	491.3762
1972	485.01893
1973	484.57262
1974	474.57575
1975	461.12064
1976	446.89893
1977	445.52403
1978	437.59437
1979	427.25305
1980	437.51974
1981	426.8905
1982	431.00301
1983	430.13548
1984	415.26833
1985	420.03509
1986	414.39931
1987	397.42098
1988	411.64301
1989	400.7551
1990	412.45549
1991	399.43057
1992	386.72898
1993	363.64787
1994	408.28572
1995	397.38689
1996	395.19848
1997	392.29492
1998	385.68657
1999	416.37455
2000	382.64311
2001	389.62323
2002	411.13751
2003	388.45873
2004	377.39846
2005	373.62904
2006	389.99663
2007	366.49554
2008	361.94527
2009	364.05549
2010	361.89428
2011	351.21096
2012	379.72618
2013	379.82669
2014	380.87384