condition mean min max ZT0-3 1.2631878333333333 0.8985735 1.593705 ZT4-7 1.2217 1.2217 1.2217 ZT8-11 0.8469015 0.8469015 0.8469015 ZT12-15 1.12327525 0.9321805000000001 1.31437 ZT16-19 1.0595175000000001 1.0595175000000001 1.0595175000000001 ZT20-23 1.53349 1.53349 1.53349