What did the before and after flow rates look like?
Sorry Bobby - missed your reply
There wasn't that much improvement, the report contained all sorts of tests results - the below figures are injector number, static flow before (I assume in ml), static flow after and the percentage difference: 
1  119  119  0.0%
2  118  119  0.85%
3  118  120  1.69%
4  117  118  0.85%
It was more a case of knowing they are working...but would have liked them all to be flowing the same as No.3!