'decrease in the rate of growth'
Yes, the OP could have been better worded.
But, the upshot is that if you look at the growth line, it has already passed its zenith.
As a numbers-lover, I would expect the next 18 months are huge markers.
Many have said that the 2015 Memorial stats were due to whatever day of the week.
I think not.
I think that the real peak of the Borg was in 2013.
They know it.
And they do not know what to do.
They are throwing into the wind.
Some SE corp gave them good advice on the SEO end of their website (their SE results are impressive). Some marketing corp gave them Mormon copycat BS that is worthless.
The 2016 Memorial stats will reflect 2015's.
After that, it's a matter of milking the blue-haired grandmas as much as possible.