66% if you're lucky!
I started an "idea" thread on the Hughes net site "Peak use speed should be minimum 95% of advertised rate"
If anyone is a member on that site then visit the page an +1 it. They closed the thread already but the votes still work and 22 people have voted making it the second most popular idea. I know its a futile effort, probably won't last long, or have any effect, but if it becomes the most popular idea then they will have difficulty removing it. Plus I'm archiving it daily.
It references a real FCC report I found - Measuring Broadband America
It states: "In 2011, the average ISP delivered 87 percent of advertised download speed during peak usage periods; in 2012, that jumped to 96 percent."