Boy Scouts of America, via the Bryan on Scouting blog, have released the rankings and numbers for all the merit badges earned during 2016. You can find the full blog post at 2016 Merit Badge Rankings Unveiled.
Radio Merit Badge came in at 74 with 6,442 earned during 2016. This is down a bit from 2015 where it was ranked 73 and 6,709. For lifetime ranking Radio Merit Badge comes in at 88th on the list with 185,633.
It will be interesting to see the impact the new requirements have in 2017. Plus, the K2BSA Jamboree operation will add roughly 300 to the numbers. Most Jamboree years result in a higher number of badges earned.
We've updated our chart at Radio Merit Badge History.