Add Manual Statistics
If you want to add your statistics manually, it's a bit more time consuming but still simple.
Under Statistics, select Add new source.
A menu will appear where you have the option of adding various data sources.
Select the add icon next to Connect a Website source.
Next up, select Manual data (estimated) as the source type and fill in the form.
Once you're done, select Add Source. Now your statistics are added to your profile!
It might take a little bit to update. So don't panic if you can't see your stats right away!