Well maybe you live in a spot where your panels get extra dirty.
I did 68.8 kWh yesterday.
My best day June 2015 was 71.8 kWh, and it was later in the month. My panels were installed in June 2015. Since days are getting longer, I bet I hit that again later this month.
And I have yet to wash my panels in 12 months of use.
I don’t think washing my panels would get me much at all if anything, and evidence is it definitely wouldn’t be 7%.