condition mean min max ZT0-3 7.9142149999999996 7.9142149999999996 7.9142149999999996 ZT4-7 7.55114 7.55114 7.55114 ZT8-11 7.816559999999999 7.816559999999999 7.816559999999999 ZT12-15 7.39708 7.39708 7.39708 ZT16-19 9.4708 9.4708 9.4708 ZT20-23 7.8 7.8 7.8