I would like to know how to calculate average daily visitors. Should it be 11 or 99 average Daily visitors?

Cafe (100 sqm)
Appendix 2: Default Occupancy Counts = 9 m2 per occupant (100/9=11 transients)
Café opening hours approx. 07-16 (9 hours)
      11 visitors that spend approx. 60 min at the café = 11 visitors per hour
      11 visitors x 9 hours = 99 visitors