(Serious Post) Can someone explains me each stereotype of each country and where they came from?

I need to know for scientific purposes :

Romania - Gyspy/Stealer 💰

Greece - Gay and black 👨đŸŋ‍❤ī¸â€đŸ‘¨đŸŋ

Serbia - Drunk đŸĨƒ

Albania - Goat fucker and black 🐐🧔đŸŋ‍♂ī¸

Slovenia - Femboys đŸ‘¯â€â™€ī¸

Croatia - Nazis 🙋đŸŧ

Bosnia - Dumb and mines everywhere 🧠

Turkey - Cockroaches đŸĒŗ

Bulgaria - Mongols 🇲đŸ‡ŗ