condition mean min max ZT0-3 18.466802 18.466802 18.466802 ZT4-7 18.0923195 18.0923195 18.0923195 ZT8-11 16.062142 16.062142 16.062142 ZT12-15 16.700088 16.700088 16.700088 ZT16-19 17.925051500000002 17.925051500000002 17.925051500000002 ZT20-23 17.574837 17.574837 17.574837