condition mean min max ZT0-3 1.364046352 0.758890903 1.9692018009999999 ZT4-7 0.8172460759999999 0.5677561554999999 1.0667359964999998 ZT8-11 0.15169275925 0.0678399485 0.23554557 ZT12-15 0.5901006285 0.5363024745 0.6438987825 ZT16-19 1.17916439725 1.077353429 1.2809753655 ZT20-23 3.3874502805 3.376062931 3.39883763