condition mean min max ZT0-3 11.787438333333334 8.560415 15.78895 ZT4-7 20.7203 20.7203 20.7203 ZT8-11 23.927300000000002 23.927300000000002 23.927300000000002 ZT12-15 34.326625 33.455799999999996 35.19745 ZT16-19 22.15885 22.15885 22.15885 ZT20-23 13.8011 13.8011 13.8011