def find_endurance_tier_iops_per_gb(volume):
    """Find the tier for the given endurance volume (IOPS per GB)

    :param volume: The volume for which the tier level is desired
    :return: Returns a float value indicating the IOPS per GB for the volume
    """
    tier = volume['storageTierLevel']
    iops_per_gb = 0.25

    if tier == "LOW_INTENSITY_TIER":
        iops_per_gb = 0.25
    elif tier == "READHEAVY_TIER":
        iops_per_gb = 2
    elif tier == "WRITEHEAVY_TIER":
        iops_per_gb = 4
    elif tier == "10_IOPS_PER_GB":
        iops_per_gb = 10
    else:
        raise ValueError("Could not find tier IOPS per GB for this volume")

    return iops_per_gb