[tor-relays] My Relay speed has dropped nearly to zero - Why?

On October 8 something caused my non-exit relay speed to drop from around 50 KB to less than 10 KB according to Atlas graphs. I have checked with my ISP and run speed tests that verify my upload speed to be .96 Mb and download to be over 3 Mb, as they have been for years. I am running Tor 0.2.4.17-rc on Windows 7 and my consensus weight has dropped to 26. What could have caused this?