condition mean min max ZT0-3 12.222826666666666 7.96298 14.577200000000001 ZT4-7 8.443585 8.443585 8.443585 ZT8-11 9.22542 9.22542 9.22542 ZT12-15 8.0272775 8.026675000000001 8.02788 ZT16-19 9.952835 9.952835 9.952835 ZT20-23 15.2323 15.2323 15.2323