condition mean min max ZT0-3 18.3 18.3 18.3 ZT4-7 5.5 5.5 5.5 ZT8-11 42.95 42.95 42.95 ZT12-15 2.3 2.3 2.3 ZT16-19 10.850000000000001 10.850000000000001 10.850000000000001 ZT20-23 8.5 8.5 8.5