def vel_zones(velocity, time):
    """
    Calculate wheelchair velocity zones

    Parameters
    ----------
    velocity : dict
        velocity data structure
    time : dict
        time data structure

    Returns
    -------
    velocity_zones : dict
        velocity zones (m/s), 1-2, 2-3, 3-4, 4-5, 5 and above

    """
    vel_1 = velocity[velocity > 1]
    vel_2 = velocity[velocity > 2]
    vel_3 = velocity[velocity > 3]
    vel_4 = velocity[velocity > 4]
    vel_5 = velocity[velocity > 5]
    per_bet_1_and_2 = abs((len(vel_2) - len(vel_1)) / len(time) * 100)
    per_bet_2_and_3 = abs((len(vel_3) - len(vel_2)) / len(time) * 100)
    per_bet_3_and_4 = abs((len(vel_4) - len(vel_3)) / len(time) * 100)
    per_bet_4_and_5 = abs((len(vel_5) - len(vel_4)) / len(time) * 100)
    per_above_5 = abs(len(vel_5) / len(time) * 100)
    zones = [per_bet_1_and_2, per_bet_2_and_3, per_bet_3_and_4,
        per_bet_4_and_5, per_above_5]
    return zones
