Sales of sugary drinks fell dramatically across five U.S. cities, after they implemented taxes targeting those drinks – and those changes were sustained over time. That’s according to a study published Friday in the journal JAMA Health Forum.

Researchers say the findings provide more evidence that these controversial taxes really do work. A claim the beverage industry disputes.

The cities studied were: Philadelphia, Seattle, San Francisco and Oakland, Calif., and Boulder, Colo. Taxes ranged from 1 to 2 cents per ounce. For a 2-liter bottle of soda, that comes out to between 67 cents to $1.30 extra in taxes.

Kaplan and his colleagues found that, on average, prices for sugar-sweetened drinks went up by 33.1% and purchases went down by basically the same amount – 33%.