Formula is counting blank cells in the range, causing averaging to give incorrect result

Hello and thanks in advance for your assistance.

I have a simple spreadsheet with data values that is updated daily. I am trying to get the following formula to properly calculate the average of "PUE" when the month is ongoing, hence blanks.

For September "SEP" the average is counting 30 days, causing the average for the month to calculate using 11 blank rows. The result should be 2.3.

Rick



=SUMIF('Data Daily'!A2:A366,"NO",'Data Daily'!C2:C366)/((COUNTIF('Data Daily'!A2:A366,"SEP")-(COUNTBLANK(A2:A366)="")))

Month PUE
Apr-14 2.4 2.4
May-14 2.3 2.3
Jun-14 2.3 2.3
Jul-14 2.2 2.2
Aug-14 2.3 2.3
Sep-14 2.3 1.4