condition mean min max ZT0-3 319.524674 319.524674 319.524674 ZT4-7 257.709118 257.709118 257.709118 ZT8-11 219.204175 219.204175 219.204175 ZT12-15 252.47105499999998 252.47105499999998 252.47105499999998 ZT16-19 286.796389 286.796389 286.796389 ZT20-23 377.926652 377.926652 377.926652