Can you specify what you mean? Like a fake 1943 Copper Cent? The ones coming from China? https://www.thesprucecrafts.com/chinese-coin-counterfeiting-ring-4071202
A friend of mine sent me this image from the 1902 mint report, that's what has me asking what was the last year for counterfeit pennies to be used as normal pennies.
I think the annual mint reports are available on the Newman Numismatic Portal. You may want to check there. Might be an interesting research project
In the articles on the recent suspension of the mutilated coin redemption program they mention the recovery of close to $6 million dollars worth of fake coins from circulation last year. No breakdown on denominations.
The Annual Reports of the Secretary of the Treasury are available at https://fraser.stlouisfed.org/title/194 Each year's report includes the report of the Director of the Mint and whatever information included. For example, in 1925, the Mint's Laboratory examined 15 counterfeit coins. No other information was given.