Year	Measure
1971	516.11075
1972	551.25812
1973	632.25097
1974	675.27411
1975	693.33805
1976	758.24382
1977	866.0208
1978	935.26492
1979	1063.67794
1980	1082.1926
1981	1046.41413
1982	1095.50332
1983	1168.98065
1984	1257.11648
1985	1302.10237
1986	1477.31277
1987	1579.66575
1988	1761.0148
1989	1857.29832
1990	2167.33961
1991	2306.64347
1992	2534.34103
1993	2814.18823
1994	2958.40773
1995	3210.13204
1996	3454.85485
1997	3726.15777
1998	3377.63507
1999	3708.70521
2000	4002.67128
2001	4033.31897
2002	4170.47615
2003	4233.48732
2004	4332.66774
2005	4364.21909
2006	4412.52712
2007	4564.98783
2008	4629.77792
2009	4649.76574
2010	5045.48775
2011	5216.58781
2012	5248.51989
2013	5231.67546
2014	5289.27583
2015	5413.34786