One frequently used basis is size of the problem: that is, 7 states account for about 45 percent of all unfiled returns (California, Florida, Illinois, New York, Oklahoma, Pennsylvania, and Texas).
The problem is that 7 states account for about 45 percent of all unfiled returns.
The mistake has been corrected in the archived article but, as is our policy, we note the error here for purposes of self-flagellation.