condition mean min max ZT0-3 6.983535 3.131925 10.835145 ZT4-7 4.67933 4.67933 4.67933 ZT8-11 1.5479 1.5479 1.5479 ZT12-15 0 0 0 ZT16-19 1.536605 1.536605 1.536605 ZT20-23 4.635695 4.635695 4.635695