Year	Measure
1971	0.02314
1972	0.02397
1973	0.02452
1974	0.02456
1975	0.0216
1976	0.02386
1977	0.0259
1978	0.02135
1979	0.02303
1980	0.02111
1981	0.03008
1982	0.02741
1983	0.02435
1984	0.02717
1985	0.02962
1986	0.02214
1987	0.01987
1988	0.02213
1989	0.02531
1990	0.02395
1991	0.02187
1992	0.02571
1993	0.02531
1994	0.01901
1995	0.02565
1996	0.0288
1997	0.02381
1998	0.02183
1999	0.02861
2000	0.0285
2001	0.02419
2002	0.0209
2003	0.01645
2004	0.02061
2005	0.02233
2006	0.02424
2007	0.02147
2008	0.03045
2009	0.0205
2010	0.02814
2011	0.02681