Year	Measure
1971	799.95714
1972	856.8417
1973	917.51607
1974	946.63819
1975	971.61444
1976	1010.63847
1977	1063.64497
1978	1158.89705
1979	1240.06848
1980	1371.29764
1981	1430.55508
1982	1463.94972
1983	1348.7459
1984	1379.77665
1985	1404.0039
1986	1338.68957
1987	1380.49851
1988	1370.44668
1989	1404.01847
1990	1448.96836
1991	1491.3029
1992	1474.00054
1993	1469.46861
1994	1474.08711
1995	1401.22954
1996	1407.54555
1997	1456.87638
1998	1474.17424
1999	1494.35948
2000	1474.59234
2001	1506.72035
2002	1495.44258
2003	1565.07765
2004	1562.08532
2005	1646.77481
2006	1659.51635
2007	1622.97112
2008	1580.66214
2009	1557.4002
2010	1489.63745
2011	1541.83407
2012	1586.61298
2013	1567.6834
2014	1513.25921
2015	1488.01791