Place a value in a defined cell across multiple tabs in a single workbook?

I am compiling a workbook that will have a massive amount of tabs. Each tab will have survey information on it. The last tab of the workbook will have the results of all of those surveys. My question is this:

Is there a way to have the workbook automatically track the amount of surveys in the workbook? I need to have the amount of surveys to find out what percent of folks gave a certain answer. Thanks!