condition mean min max ZT0-3 14.648134 14.648134 14.648134 ZT4-7 14.2477835 14.2477835 14.2477835 ZT8-11 15.0636035 15.0636035 15.0636035 ZT12-15 13.523255 13.523255 13.523255 ZT16-19 14.0609805 14.0609805 14.0609805 ZT20-23 15.4819465 15.4819465 15.4819465