condition mean min max ZT0-3 4.25212 4.25212 4.25212 ZT4-7 3.738565 3.738565 3.738565 ZT8-11 3.4397349999999998 3.4397349999999998 3.4397349999999998 ZT12-15 4.49361 4.49361 4.49361 ZT16-19 7.209695 7.209695 7.209695 ZT20-23 4.205525 4.205525 4.205525