(CNN)Spending on international transfer fees over the last decade increased from $2.66 billion in 2012 to a peak of $7.35 billion in 2019, while players' agents received $3.5 billion in commissions, a study by world governing body FIFA said.

The study said average transfer fees for players moving to a club in a different country rose steadily between 2012 and 2019 before the COVID-19 pandemic strained finances and led to a drop in 2020, when $5.63 billion was spent.