What percentage of conspiracies are true?

I was recently watching a series on Netflix called “America’s Book of Secrets”, which conjectures about whether there is a book of national secrets that exists and is held at a prominent national monument — the White House, Fort Knox, etc. The show also details the history behind such sites and the secrets questions / conspiracies that sit behind America’s history, i.e. was America’s government and democracy set up by the Freemasons as a base the create a “New World Order” that will soon come to fruition in our modern world?

The specific aforementioned scenario got me thinking about other famous conspiracy theories and have believable some of them are. This one, for example, is not so far-fetched but whether it could be considered a conspiracy is another question. George Washington, Ben Franklin, and other prominent American figures in the late 1700s were known Freemasons and likely had some sort of agenda when developing laws and culture in the newly free America, but they may not have had an agenda focused on creating a “New World Order”. They may have just wanted to create a society favorable to their way of life and/or ideals. Perhaps not such a conspiracy.

Some other prominent conspiracies are at least clearly conspiracies revolving around some sort of government cover-up. The Roswell UFO Crash of 1947, 9/11, and the JFK assasination come to mind. Undoubtedly, the conspiracy theories around a good number of events are filled with holes and are clearly lies. However, a good number seem to be rooted in healthy skepticism and have a decent amount of supporting evidence.

In summary, I feel that there are a portion of conspiracy theories that are not totally crazy and further, that I believe. Often, where there is smoke, there’s fire. My gut feel is that 20% of prominent conspiracy theories are true (or have significant elements of truth).