Percent of messages processed?

FlightAware ADS-B Flight Tracking
1

What does this line mean when it talks about messages processed vs received? Why are all messages not being processed?

http://i6.photobucket.com/albums/y210/aero83/percent.jpg

2

That’s normal.

3

10-4 thanks. Was worried it was due to running on a rpi b and lack of cpu power.