condition mean min max ZT0-3 2.1112016666666666 1.3066550000000001 2.66413 ZT4-7 0.752033 0.752033 0.752033 ZT8-11 1.448965 1.448965 1.448965 ZT12-15 2.71568 2.43881 2.99255 ZT16-19 2.6865 2.6865 2.6865 ZT20-23 4.5204699999999995 4.5204699999999995 4.5204699999999995