TAMPA, Fla. - Mitt Romney took in $21.7 million in income in 2010 and paid $3 million in taxes, a tax rate of just under 14 percent, according advanced copies of the returns that were provided to several newspapers.

The tax returns were first reported by the Wall Street Journal and Reuters early Tuesday morning.

In an initial review of the reports, ABC News' tax expert Steve Frushtick notes that based off of the reported tax rate, it appears as though the vast majority of Romney's reported income is not based off of a salary, but rather from investments. Individuals bringing in a similar income to Romney's 2010 earnings in the form of a yearly salary would pay a higher tax rate.

Frushtick gave an example using the third baseman for the New York Yankee's, Alex Rodriguez. If Rodriguez earned the exact same income as the former Massachusetts Governor, he would pay $5.3 million in taxes- a rate of 24%, because his earnings were collected in the form of a yearly salary.

The returns also show that Romney gave away $3 million in charitable donations in 2010, including $1.5 million to the Mormon Church, according to reports from the outlets who received an advanced copy. Frushtick explains that Romney could pay a lower tax rate if he were to increase that amount.

Romney's full 2010 tax return will be released later Tuesday, as will an estimate of his 2011 returns.

The campaign's decision to release the documents comes after weeks of assertions by Romney himself that he would wait until April to release them.

On Sunday, Romney changed course, announcing on Fox News Sunday that he would release them and that they had "made a mistake for holding off as long as we did."

During a press conference in Tampa on Monday, Romney was asked what went into the decision to release the returns on the same day of the State of the Union address.

"The reason that they're being released that day is that the trustee of my trust, that invests our family funds is available that day," said Romney.