*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan0002519191944
Feb1265777851452
Mar481195001207
Apr3161068001087
May105677172005859
Jun59134873490013895
Jul3945422559007140
Aug14292060002103
Sep161719001726
Oct001230001230
Nov0181100812
Dec00441218192262
Total131237681226134452340717