condition mean min max ZT0-3 0.2350935 0.2350935 0.2350935 ZT4-7 0.278517 0.278517 0.278517 ZT8-11 0.2813705 0.2813705 0.2813705 ZT12-15 0.5346679999999999 0.5346679999999999 0.5346679999999999 ZT16-19 0.3485765 0.3485765 0.3485765 ZT20-23 0.22587400000000002 0.22587400000000002 0.22587400000000002