The age distribution, , in the district of Mendrisio is: 4,222 children or 8.6% of the population are between 0 and 9 years old and 4,878 teenagers or 10.0% are between 10 and 19. Of the adult population, 4,961 people or 10.2% of the population are between 20 and 29 years old. 6,695 people or 13.7% are between 30 and 39, 8,314 people or 17.0% are between 40 and 49, and 6,307 people or 12.9% are between 50 and 59. The senior population distribution is 6,030 people or 12.3% of the population are between 60 and 69 years old, 4,470 people or 9.2% are between 70 and 79, there are 2,974 people or 6.1% who are over 80.