condition mean min max ZT0-3 7.03567 7.03567 7.03567 ZT4-7 5.061225 5.061225 5.061225 ZT8-11 4.922965 4.922965 4.922965 ZT12-15 6.42543 6.42543 6.42543 ZT16-19 9.008614999999999 9.008614999999999 9.008614999999999 ZT20-23 6.950705 6.950705 6.950705