condition mean min max ZT0-3 10.118874 10.118874 10.118874 ZT4-7 9.405244 9.405244 9.405244 ZT8-11 8.0946325 8.0946325 8.0946325 ZT12-15 10.661763 10.661763 10.661763 ZT16-19 11.2595675 11.2595675 11.2595675 ZT20-23 14.2431055 14.2431055 14.2431055