condition mean min max ZT0-3 10.795705 10.795705 10.795705 ZT4-7 12.850449999999999 12.850449999999999 12.850449999999999 ZT8-11 8.733920000000001 8.733920000000001 8.733920000000001 ZT12-15 7.914865 7.914865 7.914865 ZT16-19 14.0215 14.0215 14.0215 ZT20-23 14.25355 14.25355 14.25355