condition mean min max ZT0-3 1.6379199999999998 1.6379199999999998 1.6379199999999998 ZT4-7 0.8453455 0.8453455 0.8453455 ZT8-11 0.969258 0.969258 0.969258 ZT12-15 1.871375 1.871375 1.871375 ZT16-19 3.17374 3.17374 3.17374 ZT20-23 2.334595 2.334595 2.334595