condition mean min max ZT0-3 12.273828333333334 4.14756 18.02485 ZT4-7 4.444084999999999 4.444084999999999 4.444084999999999 ZT8-11 4.31163 4.31163 4.31163 ZT12-15 8.356505 7.977885000000001 8.735125 ZT16-19 11.23358 11.23358 11.23358 ZT20-23 14.497599999999998 14.497599999999998 14.497599999999998