condition mean min max ZT0-3 10.744783333333334 10.113185 11.537115 ZT4-7 12.47485 12.47485 12.47485 ZT8-11 16.384050000000002 16.384050000000002 16.384050000000002 ZT12-15 16.612675 16.1475 17.077849999999998 ZT16-19 16.07855 16.07855 16.07855 ZT20-23 14.459600000000002 14.459600000000002 14.459600000000002