condition mean min max ZT0-3 9.64475 9.64475 9.64475 ZT4-7 4.222865 4.222865 4.222865 ZT8-11 2.0333699999999997 2.0333699999999997 2.0333699999999997 ZT12-15 4.336589999999999 4.336589999999999 4.336589999999999 ZT16-19 7.44616 7.44616 7.44616 ZT20-23 12.84305 12.84305 12.84305