condition mean min max ZT0-3 146.014252 146.014252 146.014252 ZT4-7 198.8440655 198.8440655 198.8440655 ZT8-11 223.50187499999998 223.50187499999998 223.50187499999998 ZT12-15 211.644291 211.644291 211.644291 ZT16-19 139.6846985 139.6846985 139.6846985 ZT20-23 114.46345249999999 114.46345249999999 114.46345249999999