That's how much in music royalties goes unclaimed globally every year.
When your music plays in another country and your compositions aren't registered there, local collection societies hold your royalties. If nobody claims them within two to three years, they don't sit waiting for you. They are redistributed to the biggest publishers in the world, based on market share. Major label artists. Not you.
This isn't a fringe problem. It happens to thousands of independent artists every year, generating royalties they will never see, simply because their publishing isn't set up correctly.
Your streaming revenue is only part of what you're owed. Publishing is the other half most artists never collect.