condition mean min max ZT0-3 18.219628 18.219628 18.219628 ZT4-7 21.7286335 21.7286335 21.7286335 ZT8-11 23.7285435 23.7285435 23.7285435 ZT12-15 22.802220499999997 22.802220499999997 22.802220499999997 ZT16-19 24.865174 24.865174 24.865174 ZT20-23 22.5056245 22.5056245 22.5056245