The rate of expansion of the universe is 74.2km/sec per megaparsec
The age of the universe is 13.798 bln years
That places the furthest theoretically observable edge of universe at 13.798 bln light years away - this is how long light would take to reach us from there, and there were no light sources before that date.
Now, how fast does the observable part of the universe expand? A bit of unit conversion and multiplication:
13798000000 light years in megaparsecs = 4 230.39567 megaParsecs 
74.2km/sec in light years/year = 0.000247504559 light years / year 
Multiply the two, and I get the expansion rate:
1.04704221 light years per year per distance to the observable edge of the universe.
Speed of 1 light year per year is the speed of light. The 0.047 seems awfully small. Probably within error margin of the universe expansion speed and age of the universe estimates.
Is this a coincidence, or is this somehow bound - and if so, what are the consequences?