condition mean min max ZT0-3 26.917525 25.963700000000003 27.87135 ZT4-7 28.4744 28.4744 28.4744 ZT8-11 46.3726 46.3726 46.3726 ZT12-15 0 0 0 ZT16-19 44.1058 44.1058 44.1058 ZT20-23 50.26085 50.26085 50.26085