condition mean min max ZT0-3 9.454405 9.454405 9.454405 ZT4-7 10.297159 10.297159 10.297159 ZT8-11 9.0040625 9.0040625 9.0040625 ZT12-15 11.3574755 11.3574755 11.3574755 ZT16-19 11.809338 11.809338 11.809338 ZT20-23 12.1734565 12.1734565 12.1734565