*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970015017
1970001001
1971001001
1972000000
1973001001
1974001001
1975002002
1976013004
1977006006
1978002002
1979026008
1980003003
1981003003
1982005005
1983004004
1984003003
1985001001
1986054009
19871360010
19880460010
198921130016
19900750012
199121440020
199202550030
199312760034
19941871300101
199504090049
1996264120078
199725490065
199818880097
199903380041
200021081300123
2001072110083
200201981600214
200322821800302
200422801700299
2005071160087
200603785900437
200701682300191
20081882100110
200921735300228
20102565500113
20110733900112
201201541700171
201301312700158
201431423400179
201516110018
2016050005
2017000000
Total272851575013454