condition mean min max ZT0-3 2.423875 2.423875 2.423875 ZT4-7 1.3135 1.3135 1.3135 ZT8-11 1.17382 1.17382 1.17382 ZT12-15 2.483745 2.483745 2.483745 ZT16-19 4.835825 4.835825 4.835825 ZT20-23 2.952675 2.952675 2.952675