Year	Measure
1971	0.00308
1972	0.00341
1973	0.00372
1974	0.00412
1975	0.00423
1976	0.00421
1977	0.00433
1978	0.004
1979	0.00444
1980	0.00509
1981	0.00566
1982	0.00633
1983	0.00724
1984	0.00717
1985	0.00752
1986	0.00757
1987	0.00788
1988	0.00845
1989	0.00902
1990	0.00951
1991	0.00927
1992	0.00969
1993	0.01098
1994	0.01198
1995	0.0135
1996	0.01318
1997	0.01361
1998	0.01432
1999	0.01391
2000	0.01507
2001	0.01867
2002	0.01926
2003	0.01886
2004	0.02337
2005	0.02611
2006	0.0285
2007	0.03157
2008	0.03788
2009	0.03965
2010	0.04629