condition mean min max ZT0-3 1.2730661666666667 0.987751 1.70654 ZT4-7 0.858995 0.858995 0.858995 ZT8-11 0.819494 0.819494 0.819494 ZT12-15 0.82638775 0.7631775000000001 0.8895979999999999 ZT16-19 0.5580984999999999 0.5580984999999999 0.5580984999999999 ZT20-23 1.0975755 1.0975755 1.0975755