FYI- I have observed a drop in processing times for Petitions for alien relatives in the IR category. From a Service posted 6 months estimated processing times for IR cases, the drop has been significant in that my july IR cases are now getting approvals now- 6 weeks.
From time to time-usually in the fall- the family unit cleans up these types of visa applications to zero before letting the applications collect again. That frees up their staff for other assignments, including training.