condition mean min max ZT0-3 1.5217613333333335 1.5217613333333335 1.5217613333333335 ZT4-7 2.9648980000000003 2.9648980000000003 2.9648980000000003 ZT8-11 2.164744 2.164744 2.164744 ZT12-15 1.406817 1.406817 1.406817 ZT16-19 2.8918820000000003 2.8918820000000003 2.8918820000000003 ZT20-23 3.731031 3.731031 3.731031