Year	Measure
1960	0.02833
1961	0.02243
1962	0.01999
1963	0.01978
1964	0.02356
1965	0.02815
1966	0.02537
1967	0.02363
1968	0.02274
1969	0.01708
1970	0.02327
1971	0.01337
1972	0.0193
1973	0.01795
1974	0.02156
1975	0.01407
1976	0.01579
1977	0.01961
1978	0.01801
1979	0.02103
1980	0.02108
1981	0.02147
1982	0.0198
1983	0.01923
1984	0.01679
1985	0.02027
1986	0.02233
1987	0.01655
1988	0.02122
1989	0.01685
1990	0.01697
1991	0.01813
1992	0.01979
1993	0.01845
1994	0.02206
1995	0.01698
1996	0.01706
1997	0.01589
1998	0.02125
1999	0.01939
2000	0.01912
2001	0.01326
2002	0.01992
2003	0.01282
2004	0.01326
2005	0.01305
2006	0.01473
2007	0.01336
2008	0.01914
2009	0.01758
2010	0.01152
2011	0.01343