condition mean min max ZT0-3 8.901771666666667 5.90496 11.2097 ZT4-7 5.3964 5.3964 5.3964 ZT8-11 6.478705 6.478705 6.478705 ZT12-15 7.3316775 6.20362 8.459735 ZT16-19 7.62146 7.62146 7.62146 ZT20-23 12.12555 12.12555 12.12555