Would be a cool research project. Although IDK how this next one could be done, but I wonder out of the world population right now, how many folks have stepped foot in the city as a %(stepped in) / total population (100%). No duplicates, ((1 individual over the # of people in the world) x 100).
To get an idea, maybe one way of approximating your question, and its more an order of magnitude problem, (precision/accuracy) suffers, would be to calculate the population every 20 years. Lets assume the average time that people tend to live here and migrate elsewhere. Add up all of the people (population) every year for 100 years. Than add the tourism figures or visitors every year. Will give you an idea. 1880’s and upward the city had a significant population. I’d say 1624 to 1880 are negligible, so adding the highest population before that figure as a buffer. The latter will require research, especially for the visitors or average day/night population.
Should give you a ball park figure (again, not accurate but an idea, which is what an “order of magnitude” problem is. An example is approximating the number of grass blades on a football field. You would use a reference, like grass blades within ft2, than factor that multiple in to the square footage of a typical 120 yard football field. Its conversion heaven right there.