*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970001056
1970000000
1971000033
1972000022
1973000011
1974000011
1975000044
1976001056
1977001056
1978000033
1979000044
1980000066
1981001045
1982000044
1983001045
1984000044
1985000066
1986011079
1987011057
1988001078
1989000066
1990010067
1991004048
19920310610
19930820616
19941320915
19953200712
19960810716
199709201021
19981410612
19990140611
200002101013
20011970825
20021260413
200301140924
200401560728
20050150915
200630801021
2007171701035
2008192401044
200921150422
2010115290449
2011132501039
2012021001628
2013023106
201401420016
2015001001
2016001001
2017000000
Total161241991264604