While it may seem like there are more airline fees than ever, airlines are actually making less money from bag fees than they used to. However to make up for it, airlines are finding ways to charge fees for other things.

The U.S. Department of Transportation released a report that showed that airlines made $3.35 billion from bag fees in 2013, which was down four percent from 2012, according to the Associated Press. This showed the biggest decline since airline started charging to check luggage in 2008.

Some passengers have found ways to avoid baggage fees, which cost around $25 to $35 for domestic flights on large airlines. Some ways to avoid them include using airline credit cards or earning elite-level frequent-flier status. Some people bring smaller bags that they can carry on instead.

The report also showed that airline took in $7.3 billion in the fourth quarter of 2013, which was a reversal of a loss of $188 million during the same time in 2012. Airlines also managed to raise $2.81 billion in 2013 for fees to change a reservation or ticket, which was a 10 percent increase from the previous year. Fees such as those for checked bags, reservation changes and others, bring in big money for airlines.

Airlines didn't make much money from bags as most of the extra money simply came from large or overweight bags, but when American Airlines started to charge fees to check a regular bag or two, baggage fees all across the industry increased as other airline followed suit in 2008. The revenue from bag fees more than doubled in 2008 and doubled doubled again in 2009 and rose even higher in 2010.

The revenue feel one percent in 2011 but reached an all-time high of $3.49 billion in 2012. It has fallen since. These figures reflect the reports from 16 leading airlines in the U.S.

According to Robert Mann, a former American Airlines executive and now an aviation consultant, money from bag fees has slowed down because there is a different mix of passengers.

"You have more people exempt (from the fee) because they use the right credit card or they get status in the airline's loyalty program," Mann told AP. "The passenger who gets whacked by the bag fee is the infrequent flier."

Last year, Delta Air Lines took in the most money for bag fees as they raised $833 million. United followed with $625 million. US Airways took in $528 million and American Airlines got $506 million. Delta also made the most for ticket change fees, taking in $840 million.

However Delta Air wasn't among the airlines that made more money that in previous years. Only three airlines raised more in 2013 than they did in 2012 for bag fees. They include US Airways, Spirit Airlines and Allegiant Air. Spirit and Allegiant are airlines that also charge for carry-on bags, but they have lower airfares.