Your test isn't accurate for those of us with download speeds greater than 99 mbps. So neither are your maps.
My download speed is greater than 100 mbps (116 mbps according to Speedof.me), but your counter can only record a maximum of 99,999 kbps download speed so its reading is inaccurate. If you're relying on that to determine what broadband speeds are available around the USA, you're going to be in error. Add at least one more digit to your counter so you can get speeds up to 999,999 kbps, which should hold us for a while.