condition mean min max ZT0-3 15.95 15.95 15.95 ZT4-7 30.2 30.2 30.2 ZT8-11 16.5 16.5 16.5 ZT12-15 20.95 20.95 20.95 ZT16-19 14.700000000000001 14.700000000000001 14.700000000000001 ZT20-23 34.25 34.25 34.25