condition mean min max ZT0-3 28.52365 28.52365 28.52365 ZT4-7 24.4188 24.4188 24.4188 ZT8-11 20.74335 20.74335 20.74335 ZT12-15 20.75855 20.75855 20.75855 ZT16-19 25.333849999999998 25.333849999999998 25.333849999999998 ZT20-23 24.4613 24.4613 24.4613