In general Aviation this is known as the "differential compression
test".  It is important because it can show the condition of the engine
and indicate the particular area at fault.  While this is very important
in aircraft, imho it is less so in autos because a gas engine will start
and run fine with most of its' compression gone.  Performance,
i.e.,power on hills, will degrade with the compression as will fuel
economy, it is  a question of when you've had enough.  Also, this test
can indicate if you are nearing a catastrohic failure(based on
history).  A diesel on the other hand just won't run with compression
out of limits.  A blessing or curse.  Did you say why you did the test?
Any problems on hills or the like?

Ed Lowe
82 Westy Diesel
85 Golf Diesel
92 Cabrio