condition mean min max ZT0-3 17.0 17.0 17.0 ZT4-7 46.1 46.1 46.1 ZT8-11 8.5 8.5 8.5 ZT12-15 8.55 8.55 8.55 ZT16-19 12.899999999999999 12.899999999999999 12.899999999999999 ZT20-23 10.85 10.85 10.85