Although the variation between your figures is minimal which is good, those #'s look quite low overall and good compression is critical to a diesel. A recent test of a family members 240D was 275 PSI on one cylinder and 350 PSI on the other three.

Are the numbers you are providing PSI values?

In theory and not taking into account wear, leakage, and gauge inaccuracy:
one atmosphere = 14.7 PSI X the compression ratio (approx 21:1) = the approx. compression value in PSI. This also concurs with t walgamuth's MOTOR manual #'s.

Try posting your question in the Diesel Forum, some of the experts may offer you some valuable info.