condition mean min max ZT0-3 4.52932 4.52932 4.52932 ZT4-7 3.4572000000000003 3.4572000000000003 3.4572000000000003 ZT8-11 4.364715 4.364715 4.364715 ZT12-15 4.055804999999999 4.055804999999999 4.055804999999999 ZT16-19 4.213065 4.213065 4.213065 ZT20-23 5.02473 5.02473 5.02473