Chainalysis seems to have put up some arbitrary figure backed by no proof for cross-verification. Where does one check the addresses, they believe, belong to Darknet marketplaces / Stolen bitcoins / Scam project organizers / Other illegal activities? There is no way to check whether any address ever transacted with their suspect list either. It seems, this report is just a marketing gimmick to attract deep pocket customers.
The numbers could be totally made up, but I'm sure they have ways and means they're not going to tell us, however there's no denying a large amount of coinage has been exchanged for questionable things over the years.
If your coins are not straight from the miner the likelihood is extremely high you have a little piece of them.