Super long countif divided by super long countif

[tristandoo]

Could someone please let me know if it is possible to shrink this countif statement? It becomes too much to handle since I have to copy it for multiple different rows. The A1 stuff is to know if the sheet is "active" (if there is a different way to do this I am all ears) it would need to stay the same. The "B10" is what changes for different rows/people.
=(COUNTIF(Jan.!B10,Jan.!B10)+COUNTIF(Feb.!B10,Feb.!B10)+COUNTIF(Mar.!B10,Mar.!B10)+COUNTIF(Apr.!B10,Apr.!B10)+COUNTIF(May!B10,May!B10)+COUNTIF(Jun.!B10,Jun.!B10)+COUNTIF(Jul.!B10,Jul.!B10)+COUNTIF(Aug.!B10,Aug.!B10)+COUNTIF(Sep.!B10,Sep.!B10)+COUNTIF(Oct.!B10,Oct.!B10)+COUNTIF(Nov.!B10,Nov.!B10)+COUNTIF(Dec.!B10,Dec.!B10)+COUNTIF('Yr. Plan Mtg'!B10,'Yr. Plan Mtg'!B10))
/ (COUNTIF(Jan.!A1,Jan.!A1)+COUNTIF(Feb.!A1,Feb.!A1)+COUNTIF(Mar.!A1,Mar.!A1)+COUNTIF(Apr.!A1,Apr.!A1)+COUNTIF(May!A1,May!A1)+COUNTIF(Jun.!A1,Jun.!A1)+COUNTIF(Jul.!A1,Jul.!A1)+COUNTIF(Aug.!A1,Aug.!A1)+COUNTIF(Sep.!A1,Sep.!A1)+COUNTIF(Oct.!A1,Oct.!A1)+COUNTIF(Nov.!A1,Nov.!A1)+COUNTIF(Dec.!A1,Dec.!A1)+COUNTIF('Yr. Plan Mtg'!A1,'Yr. Plan Mtg'!A1))

 

[tristandoo]

What changes for each month?

 

[Andrew Poulsom]

The month is the DATE function's second argument (2).