According to Eurofound, almost half of Europeans aged 18 to 29 are still living with their parents.
This trend is most noticeable in countries badly affected by the financial crisis including Italy, Spain and Greece. Indeed, a shocking 79 percent of Italians aged between 18 and 29 still live at home with their parents. In Poland, that number is 64 percent while it is 49 percent in Spain.
You will find more statistics at Statista