***Population of the United States is over 300 million as the 300 millionth "American" was born last year. With that said, there are roughly 70 million folks under the age of 18.
The IRS reported recently "that as of May 4 it had received 128 million returns and processed 114 million."
That still leaves at least 102 million tax returns from people over the age of 18 that were not VOLUNTARILY submitted.
You're almost talking about half of the working population if you include everyone aged 16 and above***