condition mean min max ZT0-3 1.9778799999999999 1.692525 2.263235 ZT4-7 2.9503 2.9503 2.9503 ZT8-11 2.13197 2.13197 2.13197 ZT12-15 0 0 0 ZT16-19 3.28873 3.28873 3.28873 ZT20-23 2.62437 2.62437 2.62437