*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan00015295310
Feb00930120213
Mar0315000153
Apr112318900223
May886531200465
Jun19815747000825
Jul19720343800838
Aug504731700414
Sep5228900296
Oct2020700209
Nov0116400165
Dec001035468576
Total5515012732208834687