This is the 6905th most frequent Dutch word.
achtmaal
Eight times.
The word 'achtmaal' is used here to indicate the quantity (eight times) of the repeated action of walking up and down the stairs.
Ik heb achtmaal de trap op en neer gelopen vandaag.
I have walked up and down the stairs eight times today.
In this sentence, 'achtmaal' describes a multiplier indicating that the number of visitors this year is eight times the number of visitors last year.
Wij hebben achtmaal zoveel bezoekers als vorig jaar gehad.
We had eight times as many visitors as last year.
Here, 'achtmaal' describes the frequency of an action (taking medicine) in relation to a period (per day).