Who is the richest of them all?

Forbes finally revealed its list of the highest-earning celebrities of 2015, and for the first time, the personalities were judged only by their earnings.

The top earner is Floyd Mayweather Jr., who swept everyone away with his $300 million prize money from defeating Many Pacquiao during the May 2 Pay-Per-View boxing match. Speaking of Pacquiao, he's second on the list with $160 million.

Third is Katy Perry, whose Prismatic World tour - 126 concerts, 75 of which were held outside the United States - is the main reason for her financial success in the past year, boosting up her earnings to a total of $35 million.

Boyband One Direction trailed a little behind Katy Perry, raking in $130 million, most of which came from their world tour of 74 shows in six continents. Unfortunately they ended their tour with one member short, as Zayn Malik finally said farewell to the group last March.

Fifth on the list is "America's Got Talent Host" Howard Stern with $95 million, followed by country singer Garth Brooks with $90 million, while author James Patterson with $89 million placed seventh. "Avengers" actor Robert Downey Jr. and country-turned-pop-singer Taylor Swift were tied in the eighth place, with $80 million earnings each.

Finally, rounding out the top ten is athlete Cristiano Ronaldo. The three-time FIFA player of the year took home $79.5 million.

In case it's not yet too obvious, few females made their way in the top 100 of the highest paid celebirites. In fact, Forbes found that only 16 women made it to the list, and this shows a gender pay gap in society.

Despite Katy Perry's and Taylor Swift's lead, the women in the list made only a total of $809 million, as opposed to the $4.35 billion haul for men.

Over-all, The Guardian noted that from the list of women who made the cut, musicians fared best, claiming seven of the 16 spots. TV personalities like Ellen DeGeneres, Sofia Vergara, and Kaley Cuoco-Sweeting also made a lot of money, however, it came as a surprise that very few female actors made the list: Jennifer Lawrence and Scarlett Johansson were the only ones from film who made it to the top 100.

In a wider sense, the landscape has not changed for women so much in the last few years: men still get paid higher than women, even in a society that promotes women empowerment. Sony's former co-chair, Amy Pascal, already explained the difference during an interview with Forbes in 2013. She said, "The problem is the averages don’t work, because there are not enough parts for women to star in to get paid... So when you are looking at the total amount that women make as compared to men, it’s paltry. I think that the whole system is geared for them [women] to fail and we’re going to have to change a lot of what we do in order for that to happen."

Maybe one day, that gender pay gap will change.