condition mean min max ZT0-3 38.57235 32.01235 46.5229 ZT4-7 28.92755 28.92755 28.92755 ZT8-11 38.66865 38.66865 38.66865 ZT12-15 61.8678 56.5762 67.1594 ZT16-19 61.26519999999999 61.26519999999999 61.26519999999999 ZT20-23 73.27055 73.27055 73.27055