condition mean min max ZT0-3 4.4701933333333335 4.1217 4.724785000000001 ZT4-7 3.0501199999999997 3.0501199999999997 3.0501199999999997 ZT8-11 3.7515599999999996 3.7515599999999996 3.7515599999999996 ZT12-15 8.163409999999999 7.776465 8.550355 ZT16-19 6.17113 6.17113 6.17113 ZT20-23 8.013955 8.013955 8.013955