condition mean min max ZT0-3 14.357731 14.357731 14.357731 ZT4-7 16.081888 16.081888 16.081888 ZT8-11 13.0321635 13.0321635 13.0321635 ZT12-15 13.3833515 13.3833515 13.3833515 ZT16-19 13.720212 13.720212 13.720212 ZT20-23 14.425055 14.425055 14.425055