condition mean min max ZT0-3 2.02913 1.88136 2.218305 ZT4-7 1.0522070000000001 1.0522070000000001 1.0522070000000001 ZT8-11 0.693926 0.693926 0.693926 ZT12-15 2.730495 2.589755 2.871235 ZT16-19 3.5838099999999997 3.5838099999999997 3.5838099999999997 ZT20-23 3.830005 3.830005 3.830005