condition mean min max ZT0-3 4.0070500000000004 4.0070500000000004 4.0070500000000004 ZT4-7 2.78081 2.78081 2.78081 ZT8-11 3.137955 3.137955 3.137955 ZT12-15 3.083555 3.083555 3.083555 ZT16-19 5.28848 5.28848 5.28848 ZT20-23 4.568429999999999 4.568429999999999 4.568429999999999