This is because trends are not the same as reports:

Some stores, e.g. iTunes, provide us with trends (i.e. estimates) 24 hours after the music has gone on sale. However, it takes a further month or more for us to receive a report from them. Here you can find an overview of when we receive the reports from the stores.

The earnings on the reports are collected by us, checked and then credited to your account on the 1st of the following month.

Feel free to check the last date billed by clicking on "Reports" > "Stores" or have a look at the more detailed CSV of your reports, which will show you what stores have delivered their reports and until which date. You can then compare this to your trends. You can find the file under “Create report”.

Some stores take a lot longer to deliver trends and reports; our average wait time is three months. We appreciate your patience.