The age distribution, , in Thierrens is; 80 children or 11.9% of the population are between 0 and 9 years old and 97 teenagers or 14.5% are between 10 and 19. Of the adult population, 77 people or 11.5% of the population are between 20 and 29 years old. 101 people or 15.1% are between 30 and 39, 114 people or 17.0% are between 40 and 49, and 78 people or 11.6% are between 50 and 59. The senior population distribution is 67 people or 10.0% of the population are between 60 and 69 years old, 32 people or 4.8% are between 70 and 79, there are 22 people or 3.3% who are between 80 and 89, and there are 3 people or 0.4% who are 90 and older.