I pulled data from the GitHub API to explore this a little bit. The number of T-libs + B-unstable issues is nicely flat over time, but the median age of the open issues is increasing. Maybe try to pick up some old ones next time? Or close them, if they're sitting in the queue because no one wants them?
Data + chart here: Rust libs tracking issues history - Google Drive
I can push the Python code + cached JSON data to GitHub if people are interested.