How old are sonic and his friends

Sonic is 15, Eggman has an unknown age, Tails is 8, Amy is 12, Knuckles is 16, Charmy is 6, Vector is 20, Espio is 16, Big is 18, E-102 Gamma has an unknown age, Shadow is actually older than 50, but is physically immortal- possibly still a teenager- Rouge is 17, E-123 Omega has an unknown age, but is younger than Gamma, Cream is 6, Cheese has an unknown age, Blaze has an unknown age, as does Silverand Chip is as old as Earth itself, so about 5 billion years. Note: When discussing the E-series, I am talking about the robots, not the animals inside.