condition mean min max ZT0-3 22.053966666666664 18.2423 26.175449999999998 ZT4-7 16.1003 16.1003 16.1003 ZT8-11 14.5369 14.5369 14.5369 ZT12-15 16.3123 13.821850000000001 18.80275 ZT16-19 13.734549999999999 13.734549999999999 13.734549999999999 ZT20-23 20.49485 20.49485 20.49485