condition mean min max ZT0-3 54.011841 54.011841 54.011841 ZT4-7 98.791165 98.791165 98.791165 ZT8-11 185.973434 185.973434 185.973434 ZT12-15 337.180467 337.180467 337.180467 ZT16-19 137.188619 137.188619 137.188619 ZT20-23 218.9864325 218.9864325 218.9864325