condition mean min max ZT0-3 5.92586 5.92586 5.92586 ZT4-7 4.11823 4.11823 4.11823 ZT8-11 3.7952850000000002 3.7952850000000002 3.7952850000000002 ZT12-15 4.82441 4.82441 4.82441 ZT16-19 4.715445000000001 4.715445000000001 4.715445000000001 ZT20-23 5.411325 5.411325 5.411325