condition mean min max ZT0-3 29.537692 29.537692 29.537692 ZT4-7 33.2783525 33.2783525 33.2783525 ZT8-11 32.7610155 32.7610155 32.7610155 ZT12-15 28.574407 28.574407 28.574407 ZT16-19 27.710461000000002 27.710461000000002 27.710461000000002 ZT20-23 28.4131675 28.4131675 28.4131675