I am not sure if you have found a solution. I had trouble logging on to the forum for the past few days. Anyway, here are my notes:
I would add 2 columns. One to calculate the month number and the next using a COUNTIF formula to count the cells that contain "N/A" in each row.
At the bottom of your report I would add SUMIF formulas, one for each month, to count the totals by month from all rows.
e.g. in Cell AA1 add formula =MONTH(A1) & copy to all rows
e.g. in Cell AB1 add formula =COUNTIF(B1:Z1,"=N/A")
e.g. at the end of your data rows (this formula assumes 100 rows of data), add the SUMIF formulas for each month number =SUMIF(AA1:AA100,"=1",AB1:AB100), =SUMIF(AA1:AA100,"=2",AB1:AB100)
I hope I understood your problem.