*Excludes Observations that span multiple months

  B
b
t
W
w
 
Jan00005151
Feb01100718
Mar00540054
Apr11286000873
May1701485001556
Jun18661095001179
Jul221158600619
Aug20239900421
Sep2044200444
Oct0049500495
Nov0021700217
Dec00410133174
Total64162568401916101