Ireland has the highest share of population aged under 29 in the EU. Italy the lowest. https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Being_young_in_Europe_today_-_demographic_trends#Europe.E2.80.99s_demographic_challenge
Share of population aged 0-14 in Europe's regions - @EU_Eurostat https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Being_young_in_Europe_today_-_demographic_trends#Europe.E2.80.99s_demographic_challenge
Cyprus and Ireland have the lowest median ages in the EU (both 37.7 years). Italy (46.7) and Germany (46.0) have the highest. Median has risen in all countries since 1990. https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Being_young_in_Europe_today_-_demographic_trends#Europe.E2.80.99s_demographic_challenge
Median age of population in Europe's regions in 2018 https://ec.europa.eu/eurostat/web/products-statistical-books/-/KS-HA-19-001