condition mean min max ZT0-3 1.4564050000000002 1.4564050000000002 1.4564050000000002 ZT4-7 1.8077900000000002 1.8077900000000002 1.8077900000000002 ZT8-11 1.740935 1.740935 1.740935 ZT12-15 1.79984 1.79984 1.79984 ZT16-19 1.906675 1.906675 1.906675 ZT20-23 1.5637500000000002 1.5637500000000002 1.5637500000000002