condition mean min max ZT0-3 3.527711666666667 1.585 4.734685 ZT4-7 0.871055 0.871055 0.871055 ZT8-11 0.72041 0.72041 0.72041 ZT12-15 1.44995 1.15945 1.74045 ZT16-19 1.8536350000000001 1.8536350000000001 1.8536350000000001 ZT20-23 2.948245 2.948245 2.948245