condition mean min max ZT0-3 2.2680118333333334 0.8157755 3.27005 ZT4-7 2.62962 2.62962 2.62962 ZT8-11 1.59098 1.59098 1.59098 ZT12-15 2.20343025 1.7269355 2.679925 ZT16-19 1.6551500000000001 1.6551500000000001 1.6551500000000001 ZT20-23 1.326485 1.326485 1.326485