Year	Measure
1971	292.51184
1972	290.45846
1973	279.30013
1974	283.9078
1975	282.0062
1976	285.65237
1977	284.99517
1978	282.08249
1979	281.0767
1980	282.35955
1981	279.94448
1982	279.37898
1983	276.70351
1984	280.43762
1985	295.28501
1986	295.33949
1987	278.57722
1988	270.68186
1989	273.35806
1990	262.86972
1991	254.95084
1992	259.57638
1993	254.45457
1994	267.30472
1995	273.11323
1996	270.16325
1997	272.24536
1998	275.97075
1999	273.4086
2000	278.60068
2001	269.14516
2002	275.21265
2003	295.46262
2004	308.81203
2005	307.24581
2006	309.27502
2007	318.76903
2008	305.38961
2009	287.46311
2010	279.55062
2011	283.34691
2012	307.07573
2013	322.88627
2014	371.86891