Q:

Phrase request: Calculating with, counting with

What is the best way to describe a possibility we are assuming? I'd like to start the sentence with something like:

Counting with the rise of immigration, US population is on a rise.
Calculating in the rising number of immigrants, US population keeps growing.

Thank you.

A:

"Given" is what I think you want.  Something that is given is not necessarily true, but is assumed to be true for the sake of argument:

Given the rise in immigration, we can predict the US population will increase (over the next ten years).

Another possibility is "factor", which indicates the statistic is one of the variables used in the calculation:

Factoring in the rise in immigration, we can expect the US population to increase by 100 million over the next 20 years.

