condition mean min max ZT0-3 8.55 8.55 8.55 ZT4-7 2.9 2.9 2.9 ZT8-11 17.3 17.3 17.3 ZT12-15 19.049999999999997 19.049999999999997 19.049999999999997 ZT16-19 22.700000000000003 22.700000000000003 22.700000000000003 ZT20-23 5.8999999999999995 5.8999999999999995 5.8999999999999995