*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan00008181
Feb001512440
Mar03660069
Apr12547600502
May3881283001167
Jun13956212001181
Jul1114345700611
Aug4528300292
Sep0326800271
Oct0016200162
Nov00510051
Dec00290233262
Total322016230213384689