Year	Measure
1971	6.04389
1972	7.60035
1973	5.79712
1974	7.20837
1975	6.67877
1976	9.0301
1977	9.90934
1978	10.60289
1979	11.67046
1980	12.48141
1981	14.23043
1982	17.55596
1983	18.71742
1984	20.18689
1985	22.36313
1986	25.90471
1987	28.20218
1988	30.43584
1989	32.9625
1990	35.46779
1991	37.51613
1992	37.32217
1993	38.77729
1994	41.59652
1995	44.21308
1996	46.56816
1997	46.89635
1998	49.61432
1999	55.43638
2000	59.30691
2001	64.97866
2002	67.97919
2003	70.90003
2004	74.75469
2005	77.37823
2006	84.23084
2007	88.1943
2008	84.07659
2009	97.45297
2010	102.50475
2011	114.61131
2012	118.01117
2013	131.42609
2014	139.14368