condition mean min max ZT0-3 6.48672 5.93241 7.04103 ZT4-7 4.431505 4.431505 4.431505 ZT8-11 4.54417 4.54417 4.54417 ZT12-15 0 0 0 ZT16-19 6.004535 6.004535 6.004535 ZT20-23 5.848235 5.848235 5.848235