condition mean min max ZT0-3 2.427175 2.427175 2.427175 ZT4-7 1.6204550000000002 1.6204550000000002 1.6204550000000002 ZT8-11 2.0295199999999998 2.0295199999999998 2.0295199999999998 ZT12-15 2.6423550000000002 2.6423550000000002 2.6423550000000002 ZT16-19 4.54665 4.54665 4.54665 ZT20-23 2.95071 2.95071 2.95071