condition mean min max ZT0-3 458.054809 458.054809 458.054809 ZT4-7 452.03238350000004 452.03238350000004 452.03238350000004 ZT8-11 420.59358599999996 420.59358599999996 420.59358599999996 ZT12-15 478.849867 478.849867 478.849867 ZT16-19 460.09108449999997 460.09108449999997 460.09108449999997 ZT20-23 508.94419949999997 508.94419949999997 508.94419949999997