Recently, the major over-the-air (OTA) broadcast networks aired a speech by Donald Trump on immigration. Many news organizations and commentators contrasted this to a previous decision, in 2014, to not air a speech by Barack Obama on essentially the same topic, and to an even earlier resolution to air an immigration speech by George W. Bush.
I've been able to find that networks did air a speech by Obama about ISIS in September 2014, but that they did not air a speech by Obama on the Affordable Care Act in spring 2014. I believe I read that Bush was turned down at least once, although I can't find the article. However, I can't find a full accounting of how often they were turned down.
How many of the speeches to the nation that the two previous modern US presidents made, of the same type as Trump's speech and the ones I mentioned, were aired by the major broadcast networks? I'm asking about ABC, NBC, FOX, and CBS, but information about other companies such as Univision or local affiliates would also be relevant.