condition mean min max ZT0-3 5.259251666666667 3.793755 6.3866 ZT4-7 2.95753 2.95753 2.95753 ZT8-11 2.33493 2.33493 2.33493 ZT12-15 3.732855 3.49559 3.97012 ZT16-19 3.47242 3.47242 3.47242 ZT20-23 5.543495 5.543495 5.543495