Simplify the following text for a Grade 8 native English-speaking person.
Original: MÃ 1\/4 nster has approximately 270,000 inhabitants , and in addition more than 10,000 have their secondary residence in the city .
Simplified: It has about 270,000 inhabitants , an airport and a university . MÃ 1\/4 nster was very powerful in the Middle Ages and the Renaissance .