condition mean min max ZT0-3 14.599125 13.10355 16.0947 ZT4-7 21.2635 21.2635 21.2635 ZT8-11 30.022399999999998 30.022399999999998 30.022399999999998 ZT12-15 0 0 0 ZT16-19 32.2773 32.2773 32.2773 ZT20-23 27.49895 27.49895 27.49895