condition mean min max ZT0-3 19.19495 19.19495 19.19495 ZT4-7 17.134349999999998 17.134349999999998 17.134349999999998 ZT8-11 17.516849999999998 17.516849999999998 17.516849999999998 ZT12-15 16.31015 16.31015 16.31015 ZT16-19 16.76425 16.76425 16.76425 ZT20-23 15.27935 15.27935 15.27935