Microattentuator drop rates

Has anyone else noticed that drop rates are declining for microattenuators. Since last Sunday to this Sunday, I have received 1 paltry microattenuator. If my math is close, that's around spending 800 mod energy over the course of 70 battles...for 1 microattenuator.

This has been going on for at least the last 4 weeks. I had 19 microattenuators in mid-September when Executor event happened, and had been pushing to hit 25 so that I could upgrade a Bossk mod (which I noticed when looking at his kit after Executor event). Since that event on September 15, I am now at 24 microattenuators. That's 5 of them in just under 4 weeks, despite using full mod energy/full  10 battles a day each day. 

Seems real low drop rate, no?