condition mean min max ZT0-3 1.265132 0.829572 2.128035 ZT4-7 2.1499965000000003 2.1499965000000003 2.1499965000000003 ZT8-11 1.223498 1.223498 1.223498 ZT12-15 1.8775407499999999 1.2591315 2.4959499999999997 ZT16-19 0.9519 0.9519 0.9519 ZT20-23 0.445587 0.445587 0.445587