condition mean min max ZT0-3 28.8656 16.9547 37.013000000000005 ZT4-7 15.6691 15.6691 15.6691 ZT8-11 18.4525 18.4525 18.4525 ZT12-15 31.964999999999996 27.570549999999997 36.359449999999995 ZT16-19 37.539249999999996 37.539249999999996 37.539249999999996 ZT20-23 52.63635 52.63635 52.63635