condition mean min max ZT0-3 17.07365 16.2397 17.907600000000002 ZT4-7 13.605599999999999 13.605599999999999 13.605599999999999 ZT8-11 15.69135 15.69135 15.69135 ZT12-15 0 0 0 ZT16-19 28.56505 28.56505 28.56505 ZT20-23 19.26295 19.26295 19.26295