condition mean min max ZT0-3 15.996883 15.996883 15.996883 ZT4-7 38.237734 38.237734 38.237734 ZT8-11 29.041511 29.041511 29.041511 ZT12-15 25.2039855 25.2039855 25.2039855 ZT16-19 17.533003 17.533003 17.533003 ZT20-23 14.055085 14.055085 14.055085