condition mean min max ZT0-3 21.671025 21.126800000000003 22.215249999999997 ZT4-7 18.512349999999998 18.512349999999998 18.512349999999998 ZT8-11 21.0133 21.0133 21.0133 ZT12-15 0 0 0 ZT16-19 23.6846 23.6846 23.6846 ZT20-23 27.7395 27.7395 27.7395