condition mean min max ZT0-3 21.15 21.15 21.15 ZT4-7 39.5 39.5 39.5 ZT8-11 12.5 12.5 12.5 ZT12-15 54.599999999999994 54.599999999999994 54.599999999999994 ZT16-19 50.400000000000006 50.400000000000006 50.400000000000006 ZT20-23 22.3 22.3 22.3