You can also read the .yag file from here. The first info in the file is the title and description. The first number is the forward gain in db. The 3rd number is the actual impedance of the antenna. The 4th number is the reactance.
All measurements are in meters.
One of Lawsons 3 element yagi designs. One of Lawsons 4 element yagi designs. One of Lawsons 5 element yagi designs. One of Lawsons 6 element yagi designs. A NBS 3 element yagi designs.