condition mean min max ZT0-3 318.379292 318.379292 318.379292 ZT4-7 242.28632199999998 242.28632199999998 242.28632199999998 ZT8-11 221.10310249999998 221.10310249999998 221.10310249999998 ZT12-15 227.6321145 227.6321145 227.6321145 ZT16-19 287.443883 287.443883 287.443883 ZT20-23 301.67658 301.67658 301.67658