Nearly 20 million people watched former FBI Director James Comey testify before the Senate Intelligence Committee on TV Thursday, according to Nielsen ratings released Friday evening.

Approximately 19.5 million people tuned in, with ABC seeing the highest number of viewers at 3.295 million. CBS ranked second with 3.29 million, followed by Fox News at 3.096 million. CNN finished in fourth place with 3.05 million, just ahead of MSNBC with 2.72 million. Fox Business had 236,000 watchers while CNBC saw 184,000 viewers.

Ratings for congressional hearings are not usually tracked due to the low number of people who watch them, making it difficult to calculate the difference between the Comey event and other hearings.

Nielsen did not include online viewership in its report. Twitter partnered with Bloomberg to stream the hearing and tracked 2.7 million viewers, while Facebook reported 26 million views of its livestream of the event.

The hearing's viewership is dwarfed by other recent political events, including the presidential debates and Election Night last year.

President Trump's first speech before Congress drew 47.7 million viewers on February 28. Around 81 million people tuned in for one of the presidential debates between Trump and Hillary Clinton last fall. Just more than 71 million people watched the election returns in November, according to Nielsen.