It is not about deducting but adjusting. In an inflating currency with a constant profit margin, you are basically always going to report "record profits" because a 10% margin on $11 is nominally more than a 10% margin on $10 from a year ago but if the currency inflated 10% in that year, your profit isn't really record because it buys you the same amount of goods and services as it did a year ago.