condition mean min max ZT0-3 201.897874 201.897874 201.897874 ZT4-7 228.205305 228.205305 228.205305 ZT8-11 208.052516 208.052516 208.052516 ZT12-15 268.352462 268.352462 268.352462 ZT16-19 272.666608 272.666608 272.666608 ZT20-23 241.39935350000002 241.39935350000002 241.39935350000002