condition mean min max ZT0-3 10.797643333333333 5.64513 13.7501 ZT4-7 3.630985 3.630985 3.630985 ZT8-11 5.281124999999999 5.281124999999999 5.281124999999999 ZT12-15 6.7670175 6.73766 6.796374999999999 ZT16-19 6.831835 6.831835 6.831835 ZT20-23 12.888549999999999 12.888549999999999 12.888549999999999