Unless you've filed for an extension, today is the last day to get your taxes turned in to the IRS. Once the clock strikes midnight, those who owe will start accruing penalties -- which can range as high as 25% of your total tax bill. Tuesday also happens to be Tax Freedom Day, the day when the average American has worked enough days in the year to be freed from their tax burdens, according to the Tax Foundation's annual report. That means most Americans had to work 107 days just to earn enough money to pay their tax bills this year, and the average taxpayer has spent an average of 29% of their income on federal, state and local taxes in 2012. Taxpayers were given two extra days to file their taxes this year. While there will surely be a wave of last-minute procrastinators, most taxpayers have already filed. The IRS has received 99 million tax returns so far this season, according to the agency's latest filing statistics. That's a 2% increase from this time last year. Of those taxpayers, about 86 million, or 87%, filed electronically -- a 3% jump from last year. Most electronic filers, or 62%, used tax preparers, while 38% filed their taxes on their own. As more people file, refunds have been slipping. The average refund is $2,794 so far this season -- down about 3.5% from last year.