condition mean min max ZT0-3 2.048245 1.91535 2.30921 ZT4-7 0.772185 0.772185 0.772185 ZT8-11 1.37418 1.37418 1.37418 ZT12-15 3.2172475 2.7713900000000002 3.663105 ZT16-19 3.114675 3.114675 3.114675 ZT20-23 2.936875 2.936875 2.936875