*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan0000139139
Feb002903059
Mar03530056
Apr114346600610
May164795499005310
Jun65944610310010542
Jul367462742003524
Aug4111219001234
Sep2893000940
Oct0015200152
Nov00160016
Dec00290258287
Total124151527166042722869