Thanks for the feedback.
From the Steem Whitepaper:

SP holders are also paid interest on the balance of SP that remains vested. 15% of the yearly inflation is paid to SP holders as interest. The amount of the interest that they receive is directly proportional to the amount of SP they hold relative to the total amount of vested SP across all users.

If that has been changed please provide a source and the updated information will be reflected in the report.