How many transactions are coin tumblers responsible for?

[Bitcoin]

How many transactions are coin tumblers responsible for?

I see many resources online which explain what coin mixer or tumbler services are and how they work, and why someone would or wouldn't want to use one. But what I'm having trouble finding anywhere, is data or estimates about their overall prevalence.

What fraction of the transactions on a given blockchain, are constituted by tumbler activity? Is there any way of knowing or putting bounds on this number?

Source: How many transactions are coin tumblers responsible for?