condition mean min max ZT0-3 12.762825 12.2577 13.267949999999999 ZT4-7 10.068085 10.068085 10.068085 ZT8-11 10.07421 10.07421 10.07421 ZT12-15 0 0 0 ZT16-19 17.0434 17.0434 17.0434 ZT20-23 17.026049999999998 17.026049999999998 17.026049999999998