When using a chronograph to measure bullet speeds, averages are the best indicator of what is happening because there are variations in how the powder loads and super tiny variations can yield different speeds.
But when I measure arrow speeds off a bow (assuming fairly closely matched arrow weights), I tend to dismiss all but the top arrow speeds because the variation comes more from differences in draw and release. I put my confidence in the top arrow speeds because the bow cannot exceed that speed and thus consider that the actual measure of what truly is happening when an arrow is shot....so long as I can do my job with a good, smooth release.
Your top speeds have you shooting around 147 fps from a 45 lb bow. Most folks consider draw weight plus 100 to be a benchmark for a good shooting bow (45+100) when shooting a 10 grains per pound of draw weight bow. Your fat arrows are coming in at 11.3 grains per pound, so it is an easy assumption to say that a 450 grain arrow would spit out a fair bit faster. Nothing sluggish about this bow. You got yourself a bow I'd confidently carry to hunt big game!