Year	Avg Rate
1934	0.278
1935	0.168
1936	0.173
1937	0.276
1938	0.065
1939	0.046
1940	0.036
1941	0.129
1942	0.343
1943	0.380
1944	0.380
1945	0.380
1946	0.380
1947	0.601
1948	1.045
1949	1.115
1950	1.203
1951	1.518
1952	1.723
1953	1.891
1954	0.938
1955	1.725
1956	2.628
1957	3.225
1958	1.771
1959	3.386
1960	2.883
1961	2.354
1962	2.773
1963	3.159
1964	3.547
1965	3.949
1966	4.863
1967	4.307
1968	5.338
1969	6.667
1970	6.392
1971	4.333
1972	4.073
1973	7.032
1974	7.830
1975	5.775
1976	4.974
1977	5.269
1978	7.188
1979	10.069
1980	11.434
1981	14.025
1982	10.614
1983	8.611
1984	9.523
1985	7.479
1986	5.978
1987	5.775
1988	6.668
1989	8.112
1990	7.493
1991	5.375
1992	3.432
1993	2.998
1994	4.247
1995	5.490
1996	5.006
1997	5.061
1998	4.777
1999	4.638
2000	5.817
2001	3.388
2002	1.603
2003	1.011
2004	1.372
2005	3.147
2006	4.727
2007	4.353
2008	1.365
2009	0.150
2010	0.137
2011	0.053
2012	0.086
2013	0.058
2014	0.033
2015	0.053
2016	0.318
2017	0.931
2018	1.939
2019	2.061
2020	0.627