Logitech G27 pedal input

I’m trying to use Logitech G27 Gas pedal. When pedal isn’t pressed value is -100 and when it is pressed value is 100. Is there way to get value work between 0 and 100?

0 = pedal isn’t pressed.
100 = pedal is pressed.
_
My script looks like this:

using UnityEngine;
using System.Collections;

public class PedalTest : MonoBehaviour
{
        public float Gas;
}

void Update()
    {
        Gas = Input.GetAxis("Gas") * 100;
    }
}

Input:
90332-gas.png

_
Sorry for my bad English.

I’d say the easiest way is math.

gas = (Input.GetAxis("Gas") + 100) * 0.5f;