condition mean min max ZT0-3 6.08103 6.08103 6.08103 ZT4-7 4.13815 4.13815 4.13815 ZT8-11 3.77285 3.77285 3.77285 ZT12-15 5.212225 5.212225 5.212225 ZT16-19 6.750415 6.750415 6.750415 ZT20-23 6.42009 6.42009 6.42009