condition mean min max ZT0-3 17.242366666666666 16.64695 18.3008 ZT4-7 15.52145 15.52145 15.52145 ZT8-11 15.4516 15.4516 15.4516 ZT12-15 18.4825 18.3736 18.5914 ZT16-19 18.5571 18.5571 18.5571 ZT20-23 19.08435 19.08435 19.08435