condition mean min max ZT0-3 36.544306 36.544306 36.544306 ZT4-7 18.0699365 18.0699365 18.0699365 ZT8-11 15.5739315 15.5739315 15.5739315 ZT12-15 21.937964 21.937964 21.937964 ZT16-19 32.343391999999994 32.343391999999994 32.343391999999994 ZT20-23 46.257459 46.257459 46.257459