condition mean min max ZT0-3 13.92015 12.98695 14.85335 ZT4-7 5.09791 5.09791 5.09791 ZT8-11 8.444855 8.444855 8.444855 ZT12-15 0 0 0 ZT16-19 27.46105 27.46105 27.46105 ZT20-23 26.28465 26.28465 26.28465