Biden and Ryan at the debate in Danville on Oct. 11. (Michael Reynolds/Reuters)

About 51.4 million people watched Vice President Joe Biden’s jocular debate with GOP veep hopeful Rep. Paul Ryan Thursday, across 12 TV networks — 10 of them live at 9 p.m. EDT.

Sure, that’s about 18 million fewer people than watched the ’08 veep debate. But that debate, in which Sen. Joe Biden squared off with then Alaska Gov. Sarah Palin, was epic.

Thursday’s lively back-and-forth, moderated by ABC News’ senior foreign affairs correspondent Martha Raddatz, was one of the better watched veep debates – it clocked the biggest veep candidates’ square-off crowd since the ’84 face-off between George H.W. Bush and Geraldine Ferraro. That one logged an average of 56.7 million viewers.

Nearly 27 million of Thursday’s crowd, of more than 51 mil, were aged 55 years and older.

Just 7.2 million were aged 18-to-34 years.

The Nielsen stats include viewing via ABC, CBS, FOX, NBC, PBS, CNBC, CNN, Current TV, FOX News and MSNBC, as well as tape-delayed coverage on Telemundo and Univision.

About 10 million of Thursday night’s debate watchers went with Fox News Channel — the biggest audience of any network covering the event.

CBS was its closest competitor, with 8.31 million viewers, followed closely by ABC with 8.29 million.

NBC trailed with 7.85 million.

On the bright side, NBC seems to have done 45 percent better among advertiser preferred 18-to-49 year olds, with Joe Biden and Paul Ryan, than it did the previous Thursday with “The Office” and “Parks and Recreation,” and “Rock Center” in the same 90-minute block of time.

Sadly, the debate is a “sustained” program for the broadcast networks, because it ran without ad breaks, which means the ratings don’t count, and aren’t included in NBC’s season, weekly, or timeslot averages.

Fox broadcast network brought up the rear among commercial English-language broadcast networks, with an average of 5 million viewers tuned to the debate.

FNC’s audience was larger than CNN (4.2 million) and MSNBC (4.4 million) combined.