Welcome to GH. This has been something we've been more than aware of, but the change has been slow. In the meantime, please keep a record on your own.
Personally, I keep records 4 different ways, here, on an Excel Spreadsheet, at
www.fueleconomy.gov (So that the government/EPA gets my tank data for their info on what hybrids can do, and allows you to download the data as an Excel Spreadsheet [heck, they mention hypermilers in their giant EPA report when they revamped the MPG guidelines!]), and at
www.cleanMPG.com
You may think it's silly, but at one point, I noticed an inconsistancy between them. Turns out I had entered a tank wrong at one of them, and was able to correct it because I had it stored at multiple locations that I could check from. Plus, should one of the websites crash and lose data, I don't have to worry about it, and it's highly unlikely that I'll lose all four sources.