condition mean min max ZT0-3 13.615643 13.615643 13.615643 ZT4-7 15.508264 15.508264 15.508264 ZT8-11 17.6013805 17.6013805 17.6013805 ZT12-15 16.0969855 16.0969855 16.0969855 ZT16-19 17.614054 17.614054 17.614054 ZT20-23 16.9613405 16.9613405 16.9613405