condition mean min max ZT0-3 24.52675 24.52675 24.52675 ZT4-7 17.6116 17.6116 17.6116 ZT8-11 22.8868 22.8868 22.8868 ZT12-15 28.23785 28.23785 28.23785 ZT16-19 38.3217 38.3217 38.3217 ZT20-23 30.41995 30.41995 30.41995