Gregory Korte

USA TODAY

WASHINGTON — About 31.3 million people watched President Obama deliver his last State of the Union address on network and cable television Tuesday — the smallest audience recorded since ratings company Nielsen started keeping track in 1993.

State of the Union ratings have been in steady decline over the past two decades, gathering less than half the audience they once did. In 1993, 66.9 million people watched President Clinton's first address to a joint session of Congress. The previous record low was 31.7 viewers last year.

The ratings count the 12 networks that carried the address live: ABC, Al Jazeera America, Azteca, CBS, CNN, FOX, FOX Business Network, FOX News Channel, Galavision, MSNBC, NBC and NBC Universo. Spanish-language Univision also carried the speech on tape delay.

The state of the State of the Union address: Is it broken?

In the past, the White House has argued that the television ratings do not include other ways people follow the State of the Union address on streaming video sites like YouTube and social media channels like Facebook, Twitter and Instagram. This year, the White House added Amazon video and Snapchat to the mix.

Nielsen said 9.8 million people saw one or more of the 2.6 million tweets sent in the United States about the speech. The Twitter audience peaked at 30,600 tweets-per-minute immediately after the president's speech.