condition mean min max ZT0-3 1.42333 1.42333 1.42333 ZT4-7 1.4893649999999998 1.4893649999999998 1.4893649999999998 ZT8-11 1.1679249999999999 1.1679249999999999 1.1679249999999999 ZT12-15 1.8835000000000002 1.8835000000000002 1.8835000000000002 ZT16-19 1.74305 1.74305 1.74305 ZT20-23 1.8367 1.8367 1.8367