condition mean min max ZT0-3 3.421185 3.34382 3.49855 ZT4-7 4.625795 4.625795 4.625795 ZT8-11 6.01645 6.01645 6.01645 ZT12-15 0 0 0 ZT16-19 4.699195 4.699195 4.699195 ZT20-23 3.491725 3.491725 3.491725