condition mean min max ZT0-3 194.847441 194.847441 194.847441 ZT4-7 298.475864 298.475864 298.475864 ZT8-11 446.21924750000005 446.21924750000005 446.21924750000005 ZT12-15 603.144552 603.144552 603.144552 ZT16-19 830.941432 830.941432 830.941432 ZT20-23 869.4300195 869.4300195 869.4300195