condition mean min max ZT0-3 2.06413 1.919865 2.208395 ZT4-7 1.559925 1.559925 1.559925 ZT8-11 2.0806 2.0806 2.0806 ZT12-15 0 0 0 ZT16-19 2.555245 2.555245 2.555245 ZT20-23 2.48366 2.48366 2.48366