condition mean min max ZT0-3 4.38595 4.38595 4.38595 ZT4-7 5.87748 5.87748 5.87748 ZT8-11 3.361605 3.361605 3.361605 ZT12-15 3.11233 3.11233 3.11233 ZT16-19 2.75366 2.75366 2.75366 ZT20-23 2.967905 2.967905 2.967905