US Income Distribution

According to most recent government statistics, the population of the United States is 295,494,880. But according to another report, the number of Americans earning income is 203,400,000. I'm not sure if this is a number that represents individual tax returns or a factor imputed from some other source but for sake of argument, let's assume it's based on individual tax returns. Once again, using the same data, the report shows that the percentage of Americans earning more than $50,000 (and I'm assuming this is adjusted gross income) is 19%. Those earning more than $90,000 or more is 5.5%.