condition mean min max ZT0-3 6.574645 6.472315 6.6769750000000005 ZT4-7 4.1848 4.1848 4.1848 ZT8-11 4.175924999999999 4.175924999999999 4.175924999999999 ZT12-15 0 0 0 ZT16-19 6.086405 6.086405 6.086405 ZT20-23 6.252554999999999 6.252554999999999 6.252554999999999