condition mean min max ZT0-3 21.686025 21.4746 21.89745 ZT4-7 35.8434 35.8434 35.8434 ZT8-11 36.3713 36.3713 36.3713 ZT12-15 0 0 0 ZT16-19 24.96385 24.96385 24.96385 ZT20-23 32.8851 32.8851 32.8851