Ardours Numbers

What do the numbers at the top of Ardour when it is operating mean???

For instance there is 48kHz/2.7ms

Buffers p:74%



Diske etc

Now it is all pretty self explanatory except for the one c:99%

Can anyone tell me what that means please???

Thanks in advance

p is playback buffer and c is capture buffer.
cheers pete

Thanks retep!