condition mean min max ZT0-3 18.25 18.25 18.25 ZT4-7 1.0 1.0 1.0 ZT8-11 6.45 6.45 6.45 ZT12-15 14.6 14.6 14.6 ZT16-19 10.700000000000001 10.700000000000001 10.700000000000001 ZT20-23 10.35 10.35 10.35