Update variable php when every time when it increas in function or loop

I have a php variable, which I want to use as a counter to see how many percent of a loop / function-this function has a long response time, was executed. This variable is displayed on the page. The problem is that the variable does not update until the cycle or function has ended. How can I update the variable while the function is running or in the cycle? Url example code: https://ufile.io/agfi8ksj