condition mean min max ZT0-3 13.860916666666666 4.589449999999999 18.78785 ZT4-7 4.665305 4.665305 4.665305 ZT8-11 7.09379 7.09379 7.09379 ZT12-15 10.7848 8.301855 13.267745000000001 ZT16-19 14.9009 14.9009 14.9009 ZT20-23 16.33565 16.33565 16.33565