condition mean min max ZT0-3 11.95 11.95 11.95 ZT4-7 4.0 4.0 4.0 ZT8-11 4.4 4.4 4.4 ZT12-15 17.55 17.55 17.55 ZT16-19 13.850000000000001 13.850000000000001 13.850000000000001 ZT20-23 3.65 3.65 3.65