How to create an auto incrementing number based upon checkbox

Hi everyone,

I have a smartsheet where each row represents an "installation". One of the columns is called "Gone Live" and is of a type checkbox. I have created another column entitled "Number of Installs this year".

In this column, I want to create a formula that checks the "Gone Live" field, and if the checkbox is ticked, then automatically increment a number, representing the number of installs so far.

Any suggestions for how I achieve this would be greatly appreciated.