condition mean min max ZT0-3 15.7194 15.7194 15.7194 ZT4-7 14.3812 14.3812 14.3812 ZT8-11 15.11895 15.11895 15.11895 ZT12-15 18.57945 18.57945 18.57945 ZT16-19 18.6938 18.6938 18.6938 ZT20-23 19.8377 19.8377 19.8377