condition mean min max ZT0-3 8.236384999999999 7.5886 8.88417 ZT4-7 8.97993 8.97993 8.97993 ZT8-11 18.14595 18.14595 18.14595 ZT12-15 0 0 0 ZT16-19 16.32285 16.32285 16.32285 ZT20-23 8.883635 8.883635 8.883635