I'm pretty sure nobody publishes that data. Other than there are approximately 3000 arrests annually.
The IRS CI are involved with Legal Source Tax Crimes (basically tax cheaters that probably don't involve violence); Illegal Source Financial Crimes (All types of fraud and tax evasion, such as illegal gambling or casinos or currency crimes); and Narcotics Related and Counterterrorism Financial Crimes (money laundering or financing of terrorist activity).
The ATF is mainly responsible for enforcing illegal stills now. It's been a long time since the Treasury "T men" and also US Marshalls chased after moonshiners and bootleggers. Now moonshiners have their own reality TV shows. As I'm sure you know, Treasury Agents (now the mainly IRS) are about making sure Uncle Sam gets his money. Some of them are very organized criminal organizations with weapons.
One might ask why the FBI doesn't handle arresting tax cheats and the like. You need a time machine to go back and ask J Edgar Hoover that question.
State and local law enforcement are generally not qualified or staffed to investigate financial crimes. They bring in Feds for that.
More broadly, lots of Federal government agencies have agents that carry arms. The Fish and Wildlife Service, Bureau of Land Management and Park Service, the EPA, Postal Inspectors, Federal Reserve agents, NOAA, NIH, and even the Library of Congress have armed groups. There are many more. Nothing new about any of that. Some may find it interesting that in many states railroad bulls (cops) are often armed and have arrest authority and can arrest without a warrant.
The NC Wildlife gal in my area who checks people for fishing licenses has a Glock strapped to her duty belt. I'm fine with that. She noticed the shotgun racked to the center console on my skiff and thought it was cool.
My Godfather was an FBI agent. After graduating from the Academy at Quantico he was not involved in any activity involving firearms during his entire 25 years.
Fun fact: It wasn't until 1934 that FBI agents were given authority to carry firearms.
They were given the authority to carry right after prohibition ended, to arrest illegal alcohol production as it evaded tax.
We have other federal departments that handle that now, so we don't need heavily armed, untrained tax accountants.
There are no legit reason for a tactical IRS agent. They don't do armed raids, or shootouts with white collar tax criminals.
That's just rediculous.
The feds handle prosecution for financial crimes.
The armed raids are done by local LEO, with Feds on scene to preserve evidence for court, and chain of custody.
Though after a few cups of coffee, I think this is just the Feds buying up overrun ammo from the Lake City plant, because Joe Biden just announced he doesn't want the ammo sold to the public any longer.
He thinks M855 green tip is some sort of special super duper ammo, and he wants us disarmed.
Lake City is just the only ammo plant he can bully.