I agree FF. I think setter has possibly made mistake. Pollen Count would've been perfect.
Respect to Danny though... Good thinking. I hope we find out!....
'add up' could be AGGREGATE (as in the verb) or a dodgy SUMMARIES for the second word but I can't think of anything appropriate for the first word.
Might be worth checking with the setter whether there has been a correction to the letter count to 6,5.