condition mean min max ZT0-3 0.9249041666666666 0.683493 1.25637 ZT4-7 1.1426105 1.1426105 1.1426105 ZT8-11 1.2952050000000002 1.2952050000000002 1.2952050000000002 ZT12-15 4.453412500000001 4.04066 4.8661650000000005 ZT16-19 3.3567150000000003 3.3567150000000003 3.3567150000000003 ZT20-23 1.764815 1.764815 1.764815