condition mean min max ZT0-3 166.561971 166.561971 166.561971 ZT4-7 167.858853 167.858853 167.858853 ZT8-11 143.7074635 143.7074635 143.7074635 ZT12-15 107.473487 107.473487 107.473487 ZT16-19 125.21850649999999 125.21850649999999 125.21850649999999 ZT20-23 89.642 89.642 89.642