To count as high-rise, the building has to be at least 250 feet or 75 meters tall. Cities with less than 10 high rise buildings were not taken into account for this quiz.
For the main cities of agglomerations of which the skyline is considerably influenced by high-rise buildings in neighboring municipalities, I've conjoined numbers.
Data is mainly derived from skyscraperpage.com, and might not be perfectly up to date. Please let me know if any corrections can be made.