Listener and apparent math wizard Lukas has put together some amazing charts that show off some interesting data about Relay shows:
As you can see, Under the Radar and Clockwise are very consistent as far as episode length, which makes a lot of sense as their duration is built in to the format. Other shows see larger spreads, with Reconcilable Differences and Cortex being the shows with the longest runtimes.
Here's Lukas:
Relay FM spans 22 shows and a combined runtime of over 53 days spread across 1091 episodes since 2014.
In 2015, there were 670 episodes published, and based on the average release frequencies, there will probably be 888 episodes in 2016. We’re currently about 15% of the way there at 135 episodes: