condition mean min max ZT0-3 7.952645 7.66807 8.23722 ZT4-7 4.741135 4.741135 4.741135 ZT8-11 3.5014000000000003 3.5014000000000003 3.5014000000000003 ZT12-15 0 0 0 ZT16-19 6.142424999999999 6.142424999999999 6.142424999999999 ZT20-23 5.416125 5.416125 5.416125