condition mean min max ZT0-3 13.316966666666668 12.299150000000001 14.408850000000001 ZT4-7 17.998649999999998 17.998649999999998 17.998649999999998 ZT8-11 24.640700000000002 24.640700000000002 24.640700000000002 ZT12-15 29.2809 28.925449999999998 29.63635 ZT16-19 24.838549999999998 24.838549999999998 24.838549999999998 ZT20-23 17.2485 17.2485 17.2485