condition mean min max ZT0-3 26.57295 26.57295 26.57295 ZT4-7 18.63395 18.63395 18.63395 ZT8-11 23.6672 23.6672 23.6672 ZT12-15 21.4189 21.4189 21.4189 ZT16-19 35.40655 35.40655 35.40655 ZT20-23 26.374299999999998 26.374299999999998 26.374299999999998