ILoveTTATT2: If I had made a similar survey in 1985 regarding the people baptized in the 1970's, it is possible that the average response would be closer to the 15 years difference.
Sure it's "possible," if they all left in the early '80s. This is not only logically absurd, it ignores the historical facts what actually happened to the membership of the JW religion post-1975. Not only is it NOT what happened, your response
Do you not know how to calculate a mathematical average and (more importantly) what it means? There are three kinds of averages: mean, mode and median. They are different and have corresponding applications depending on what one is trying to measure and report.
That notwithstanding: gathering, collating and correctly interpreting statistical data is significantly more complex than the informal survey you are conducting here.
I was trying to be a helpful, but your response shows a lack of interest in approaching this in a scientific manner.
Have you heard? There are three kinds of people in the world: those that are good at math and those that aren't.