rate of the flow of a count?

hello, hope all is well.: )

I have a flonum number box which displays a count/stream of numbers always in a logical order 1,2,3,4,5,6,7,8,9,... it can change direction however 9,8,7,6,5,4,3,2,1....etc. And can go both ways 9,8,7,6,5:6,7,8,9:8,7,6,5,4,3:4,5,6,7

Although the numbers are always in a logical order the speed of the rate of which they change varies all the time. (the speed and acceleration) But the present speed is what I am hoping to find out.

for example, if the numbers count each second 1 2 3 4 5 6 the module will output a 1

I thought to perhaps sample whole numbers or fractions and use a timer to measure the time it takes to reach these points?

Or maybe there is a module out there that measures the flow/rate/speed of a count?.

thanks for any help : )