Year	Measure
1960	0.0048
1961	0.00596
1962	0.00659
1963	0.0086
1964	0.00798
1965	0.00805
1966	0.0173
1967	0.01651
1968	0.01352
1969	0.0202
1970	0.02578
1971	0.02581
1972	0.02595
1973	0.02145
1974	0.0225
1975	0.01915
1976	0.01766
1977	0.01782
1978	0.02731
1979	0.03216
1980	0.03036
1981	0.03011
1982	0.03126
1983	0.02043
1984	0.02488
1985	0.02428
1986	0.02789
1987	0.02389
1988	0.02025
1989	0.01618
1990	0.01497
1991	0.026
1992	0.0183
1993	0.01875
1994	0.02113
1995	0.02843
1996	0.03476
1997	0.03084
1998	0.02936
1999	0.0361
2000	0.0289
2001	0.01634
2002	0.02174
2003	0.03688
2004	0.03604
2005	0.03857
2006	0.04495
2007	0.01979
2008	0.02522
2009	0.0408
2010	0.05647
2011	0.02892