condition mean min max ZT0-3 1278.746667 1278.746667 1278.746667 ZT4-7 1048.4922222333335 1048.4922222333335 1048.4922222333335 ZT8-11 1631.607778 1631.607778 1631.607778 ZT12-15 2546.0088889999997 2546.0088889999997 2546.0088889999997 ZT16-19 2737.4344446666664 2737.4344446666664 2737.4344446666664 ZT20-23 1622.701111 1622.701111 1622.701111