condition mean min max ZT0-3 26.75 26.75 26.75 ZT4-7 23.0 23.0 23.0 ZT8-11 34.599999999999994 34.599999999999994 34.599999999999994 ZT12-15 11.4 11.4 11.4 ZT16-19 9.4 9.4 9.4 ZT20-23 14.899999999999999 14.899999999999999 14.899999999999999