*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan0004908912
Feb003450363708
Mar181122001131
Apr1451869001915
May26591907001992
Jun1471131695001955
Jul180181259001457
Aug7113981001065
Sep15494300962
Oct3064300646
Nov1053200533
Dec00213111071321
Total445260115095237814597