condition mean min max ZT0-3 19.549999999999997 19.549999999999997 19.549999999999997 ZT4-7 14.5 14.5 14.5 ZT8-11 18.700000000000003 18.700000000000003 18.700000000000003 ZT12-15 15.15 15.15 15.15 ZT16-19 18.049999999999997 18.049999999999997 18.049999999999997 ZT20-23 13.950000000000001 13.950000000000001 13.950000000000001