condition mean min max ZT0-3 232.385903 232.385903 232.385903 ZT4-7 248.017421 248.017421 248.017421 ZT8-11 242.5902825 242.5902825 242.5902825 ZT12-15 206.223549 206.223549 206.223549 ZT16-19 300.27115449999997 300.27115449999997 300.27115449999997 ZT20-23 211.92548 211.92548 211.92548