condition mean min max ZT0-3 21.52595 21.52595 21.52595 ZT4-7 16.21905 16.21905 16.21905 ZT8-11 17.5103 17.5103 17.5103 ZT12-15 19.521700000000003 19.521700000000003 19.521700000000003 ZT16-19 22.05305 22.05305 22.05305 ZT20-23 25.7986 25.7986 25.7986