Year	Measure
1960	0.00306
1961	0.00376
1962	0.00326
1963	0.00596
1964	0.00456
1965	0.00588
1966	0.00617
1967	0.00616
1968	0.00803
1969	0.00853
1970	0.00735
1971	0.00619
1972	0.00744
1973	0.00591
1974	0.00745
1975	0.01282
1976	0.0178
1977	0.01784
1978	0.01902
1979	0.02051
1980	0.02212
1981	0.02404
1982	0.02637
1983	0.02063
1984	0.02387
1985	0.02097
1986	0.02026
1987	0.03118
1988	0.04761
1989	0.02899
1990	0.03677
1991	0.03542
1992	0.04078
1993	0.05125
1994	0.04541
1995	0.05192
1996	0.05818
1997	0.05632
1998	0.05881
1999	0.04756
2000	0.04173
2001	0.03199
2002	0.04425
2003	0.04579
2004	0.05893
2005	0.04992
2006	0.05508
2007	0.04404
2008	0.04033
2009	0.04303
2010	0.06122
2011	0.0608