*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan00003636
Feb002401236
Mar02924000269
Apr11722900247
May66014000647
Jun9289170002970
Jul71318542001867
Aug8212700137
Sep00890089
Oct01760077
Nov00390039
Dec00906372
Total314859148501116486