condition mean min max ZT0-3 5.3 5.3 5.3 ZT4-7 2.0 2.0 2.0 ZT8-11 3.45 3.45 3.45 ZT12-15 1.75 1.75 1.75 ZT16-19 1.9500000000000002 1.9500000000000002 1.9500000000000002 ZT20-23 1.6500000000000001 1.6500000000000001 1.6500000000000001