condition mean min max ZT0-3 2.53641 2.53641 2.53641 ZT4-7 1.8814899999999999 1.8814899999999999 1.8814899999999999 ZT8-11 2.42682 2.42682 2.42682 ZT12-15 3.449265 3.449265 3.449265 ZT16-19 4.936170000000001 4.936170000000001 4.936170000000001 ZT20-23 3.28471 3.28471 3.28471