condition mean min max ZT0-3 3.0608375 2.89931 3.222365 ZT4-7 5.436065 5.436065 5.436065 ZT8-11 5.881355 5.881355 5.881355 ZT12-15 0 0 0 ZT16-19 4.55481 4.55481 4.55481 ZT20-23 6.62298 6.62298 6.62298