condition mean min max ZT0-3 5.721585 3.58137 7.86519 ZT4-7 3.7416899999999997 3.7416899999999997 3.7416899999999997 ZT8-11 3.853045 3.853045 3.853045 ZT12-15 4.3920175 3.20252 5.581515 ZT16-19 5.030725 5.030725 5.030725 ZT20-23 6.441045 6.441045 6.441045