Hello,

It is showing publishing rate,

average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00000s window: 2
average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00009s window: 3
average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00010s window: 4
average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00010s window: 5
average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00009s window: 6
average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00010s window: 7
average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00010s window: 8
average rate: 1.000
    min: 1.000s max: 1.000s std dev: 0.00010s window: 9

Min max is the same.

What factors will change rate more than you specified 20Hz.

- Prasad