condition mean min max ZT0-3 0.2871245 0.2871245 0.2871245 ZT4-7 0.3339545 0.3339545 0.3339545 ZT8-11 0.4727015 0.4727015 0.4727015 ZT12-15 0.44060199999999994 0.44060199999999994 0.44060199999999994 ZT16-19 0.807871 0.807871 0.807871 ZT20-23 0.5440535 0.5440535 0.5440535