condition mean min max ZT0-3 21.656633333333332 12.39815 26.301450000000003 ZT4-7 15.259450000000001 15.259450000000001 15.259450000000001 ZT8-11 18.959400000000002 18.959400000000002 18.959400000000002 ZT12-15 17.357275 16.629800000000003 18.08475 ZT16-19 21.5619 21.5619 21.5619 ZT20-23 28.6054 28.6054 28.6054