Agent speed is not proportional

Hi. I'm working in a project and when I tried to play with NaveMesh agent's speed, I saw their speeds aren't proportional to each other. For example, if I put an agent with a velocity of 1, and another with a velocity of 0.5, the second agent doesn't go at the half speed of the first, it's just go like at a quarter of the first agent's speed. Does anyone know how to solve it? Thank you.


Extra Data: They don't have any acceleration (but they work exactly the same with or without acceleration) and I'm using Unity's Third Person Controller Scrip, so my characters have animations.