Typical throughput on these is 100-200Mbps so yours is on the low side but it depends on distance, wiring quality and interference. Make sure you plug directly into wall sockets and don't use extension leads. Try them in the same room and see what you get. Common interference sources are switch mode power supplies (such as mobile phone chargers). I improved performance measurably by putting all my mains adaptors, TVs, Xbox, etc into multi gang adaptors and then fitting the power leads to those with clip on ferrite inductors / interference filters from Amazon.