Which of the following is most appropriate unit to describe the rate which people are entering a theme park?

It could have been oh so much easier to choose the best choice
if you had but told me what the choices are.

The most appropriate choice depends on why you want to know,
and what you plan on doing with the information.  Are you going to
use it to help you decide ...

-- How many entrance gates to build ?
-- How many ticket-takers to hire ?
-- What size parking lot is needed ?
-- How much ice cream and beer to stock in the park each day ?
-- How many rest rooms the park needs ?
-- How many costumed characters should roam the park ?
-- How many police should patrol the park ?
-- How much the park needs to be advertised in the next 6 months ?
-- Whether it will pay to build another similar park somewhere else ?

Depending on the application, here are some appropriate units
to describe the rate at which people are entering a theme park:

-- visitors per minute
-- visitors per hour
-- visitors per day
-- visitors per week
-- visitors per month
-- visitors per year