Year	Measure
1971	297.92454
1972	311.12894
1973	311.92287
1974	290.88787
1975	298.71631
1976	295.18561
1977	287.01422
1978	297.28805
1979	303.32979
1980	301.57857
1981	302.81389
1982	315.63085
1983	312.69911
1984	317.59507
1985	308.75494
1986	314.44921
1987	322.00233
1988	322.08223
1989	318.78029
1990	318.30775
1991	319.25315
1992	323.87851
1993	337.87497
1994	321.4121
1995	329.10107
1996	365.77804
1997	376.92892
1998	381.23364
1999	404.95459
2000	443.32406
2001	425.60429
2002	430.11648
2003	451.82411
2004	454.14922
2005	460.99118
2006	461.74211
2007	467.44347
2008	456.96675
2009	450.61082
2010	482.28056
2011	514.7852
2012	551.02071
2013	487.37843
2014	515.68475