condition mean min max ZT0-3 15.335377 15.335377 15.335377 ZT4-7 14.476194 14.476194 14.476194 ZT8-11 21.083518499999997 21.083518499999997 21.083518499999997 ZT12-15 16.9265715 16.9265715 16.9265715 ZT16-19 15.6035955 15.6035955 15.6035955 ZT20-23 13.9961525 13.9961525 13.9961525