condition mean min max ZT0-3 2.4562475 2.316275 2.5962199999999998 ZT4-7 0.6187365 0.6187365 0.6187365 ZT8-11 1.400453 1.400453 1.400453 ZT12-15 0 0 0 ZT16-19 1.2153960000000001 1.2153960000000001 1.2153960000000001 ZT20-23 2.134045 2.134045 2.134045