*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan00004141
Feb011101628
Mar00290029
Apr11111168001190
May648642799003511
Jun7271281797002652
Jul12791353167004581
Aug199201138001357
Sep71246900542
Oct3058900592
Nov1022900230
Dec0024084108
Total293936111420014114861