What % of ETF investors lose money?

It is often said that around 70% of private investors lose money when investing. I'm not sure, but assume this value applies to stock trading. Is there any evidence/studies as to what % of people who invest in an ETF lose money? I think the percentage will be significantly lower, but I would like to know how big the risk of making a loss actually is in the end. Does anyone have any experience with this or knows where to get one?