*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan0230104109
Feb002212447
Mar35145800107
Apr983725900394
May1121954300674
Jun10548908001061
Jul652057400659
Aug17740800432
Sep0019700197
Oct00560056
Nov00310031
Dec10330403437
Total433147309215314204