The NIH scoring system changed in 2009. The current system uses integer values, where 1 is the best score and 9 is the worst.
It is important that you read and follow the guidelines in the scoring document  and the Program Project Review Criteria described in the FOA . The numeric scores that you give should correspond well with your written critiques.
For each individual subproject:
For each core, you will provide a non-numeric rating of low, moderate, or high impact. The Scientific Review Officer (SRO) may ask you to use a numeric score only for the purposes of electronic scoring.
For the overall program project, you will provide a score between 1 and 9. The scores of all reviewers are averaged and multiplied by 10 to produce a final score of between 10 and 90. The overall score should take into consideration the five criteria and synergies among the components of the program project (cores and subprojects), but the final score does not have to be an average of the scores of the subprojects.