 In 1982, the composition of the coin was changed to the current 99.2% zinc and 0.8% copper core alloy with a plating of pure copper, resulting in a 20% weight reduction.After the setback, the US Mint recalled the coins, but about 12 to 14 aluminum cents were never returned to the mint.No oversight, record keeping, or statement that the coins had to be returned was made by the US Mint as examples were handed out.