condition mean min max ZT0-3 33.885149999999996 33.4051 34.3652 ZT4-7 27.479750000000003 27.479750000000003 27.479750000000003 ZT8-11 31.700850000000003 31.700850000000003 31.700850000000003 ZT12-15 0 0 0 ZT16-19 33.91315 33.91315 33.91315 ZT20-23 31.97385 31.97385 31.97385