condition mean min max ZT0-3 17.0927 17.0927 17.0927 ZT4-7 15.700600000000001 15.700600000000001 15.700600000000001 ZT8-11 9.512635 9.512635 9.512635 ZT12-15 8.873429999999999 8.873429999999999 8.873429999999999 ZT16-19 11.6323 11.6323 11.6323 ZT20-23 15.24595 15.24595 15.24595