condition mean min max ZT0-3 24.705695 24.705695 24.705695 ZT4-7 17.734122499999998 17.734122499999998 17.734122499999998 ZT8-11 18.0358285 18.0358285 18.0358285 ZT12-15 19.4240085 19.4240085 19.4240085 ZT16-19 26.615873999999998 26.615873999999998 26.615873999999998 ZT20-23 32.1141365 32.1141365 32.1141365