condition mean min max ZT0-3 7.895875 7.895875 7.895875 ZT4-7 4.980155 4.980155 4.980155 ZT8-11 9.01384 9.01384 9.01384 ZT12-15 9.326105 9.326105 9.326105 ZT16-19 9.20559 9.20559 9.20559 ZT20-23 7.559115 7.559115 7.559115