The third value is the difference between the pressure reading measured when the value is closed and fully open. The second value is the MAP sensor, the difference between the two MAP readings with the valve closed and open is shown in field 3.
If the difference is too small then there may be a leak through the valve when it is closed or the valve may be faulty (e.g. stuck, not moving correctly)
I would suggest running the EGR valve adaptation. Switch off. Then repeat the test. If it still fails then there is a problem with the EGR.
http://wiki.ross-tech.com/wiki/index.php/Exhaust_Gas_Recirculation_(EGR)_Valve_Adaptation
Check the metal pipe from the valve to the throttle for any leaks. If its OK, you can take the valve off and have a look to see what the condition is.
You can try cleaning it with EGR cleaner, but technical documentation from the manufacturer of the part says that the valve should not be cleaned. They say that if it doesn't work properly then it should be replaced, cleaning would not help and can damage the valve.
As it doesn't work now, cleaning it cannot do any more harm. If it fixes the problem (re-run the adaptation after cleaning) then great, if not, you will likely need a replacement.
regards
Andrew