The age distribution, , in Gressy is; 18 children or 11.6% of the population are between 0 and 9 years old and 26 teenagers or 16.8% are between 10 and 19. Of the adult population, 16 people or 10.3% of the population are between 20 and 29 years old. 20 people or 12.9% are between 30 and 39, 24 people or 15.5% are between 40 and 49, and 15 people or 9.7% are between 50 and 59. The senior population distribution is 18 people or 11.6% of the population are between 60 and 69 years old, 12 people or 7.7% are between 70 and 79, there are 5 people or 3.2% who are between 80 and 89, and there is 1 person who is 90 and older.