On the Plot Scale under Page Setup, the pull down menu does not have something to plot 3/4 size. I see a 1:1 for full size, 1:2 for half size and so on but nothing for 3/4. Also, we usually use only 5 sizes 1:1, 1:2, 1/8 scale, 1/4 scale, 1/16 scale (except for engineering scale) . How can you minimize the number of plot scales on the pull down menu?