condition mean min max ZT0-3 3.534625 3.534625 3.534625 ZT4-7 3.21188 3.21188 3.21188 ZT8-11 3.192085 3.192085 3.192085 ZT12-15 4.98137 4.98137 4.98137 ZT16-19 5.379575 5.379575 5.379575 ZT20-23 5.067745 5.067745 5.067745