condition mean min max ZT0-3 2.07388 2.07388 2.07388 ZT4-7 0.830945 0.830945 0.830945 ZT8-11 2.5407 2.5407 2.5407 ZT12-15 7.684855000000001 7.684855000000001 7.684855000000001 ZT16-19 5.5870750000000005 5.5870750000000005 5.5870750000000005 ZT20-23 3.91542 3.91542 3.91542