In the late 1990s, United States Treasury Officials estimated that up to $20,000 worth of counterfeit bills were being passed in New York City each week.
By 2010, officials estimated that up to $200,000 worth of fake bills were being passed every week.
(Additional statistics about counterfeit dollars being passed into circulation.)
Source: Jim Dwyer, “Awash in $100 Bills That Add Up to Zero,” New York Times, April 23, 2010.