Follow me here. According ti Statista, global GDP is approximately 105 trillion US dollars per year and climbing.
https://www.statista.com/statistics/268750/global-gross-domestic-product-gdp/
Currently, the UNODC estimates 2.7% of global GDP is a result of laundered cash.
https://syntheticdrugs.unodc.org/syntheticdrugs/en/cybercrime/launderingproceeds/index.html
That's more than 2.8 trillion US dollars per year (and climbing).
What's important to remember, is that the total amount of dollars stored off the books is much higher.
This cash,of course, isn't explicitly from the drug trade, but from all illicit trade.
