Year	Measure
1971	10.75062
1972	11.82823
1973	18.62751
1974	16.94164
1975	18.06953
1976	19.41937
1977	21.26148
1978	46.25507
1979	24.87201
1980	27.70929
1981	31.9361
1982	17.56747
1983	36.63413
1984	32.47676
1985	33.42292
1986	31.10451
1987	30.86921
1988	36.16635
1989	33.81732
1990	34.95031
1991	36.7026
1992	38.82364
1993	39.11794
1994	39.37545
1995	41.82501
1996	44.46808
1997	47.91743
1998	44.82042
1999	51.92
2000	58.11285
2001	61.46904
2002	68.26225
2003	64.62289
2004	70.32254
2005	73.78895
2006	75.08918
2007	79.71811
2008	86.35245
2009	87.87321
2010	95.44247
2011	91.53558
2012	93.12212
2013	96.75693
2014	100.22639