I said "claims" because, for reasons too tedious to list, I don't think they do know or can know a very exact percentage (even to +/- 10%).
And note, they're talking about "number of items" (not "amount of debris" as you say -- that would imply mass, a different thing).
But if it's anywhere near half of the "number of items", then these two crashes alone are a highly significant source of junk. I did not know that, and that seemed worth a link.
And note, they're talking about "number of items" (not "amount of debris" as you say -- that would imply mass, a different thing).
But if it's anywhere near half of the "number of items", then these two crashes alone are a highly significant source of junk. I did not know that, and that seemed worth a link.