condition mean min max ZT0-3 16.784525 15.729 17.840049999999998 ZT4-7 14.35995 14.35995 14.35995 ZT8-11 14.7349 14.7349 14.7349 ZT12-15 0 0 0 ZT16-19 16.486449999999998 16.486449999999998 16.486449999999998 ZT20-23 17.51005 17.51005 17.51005