GrinScan Charts : What is the meaning?

Hi guys, my first post on grin-forum. I am interested in learning more about grin and I am a bit confused about the mining rate charts posted on https://grinscan.net/charts .

What is the meaning of these charts?

In particular the estimated mining rate seems awfully high: 535k gps !!
Is that right?

I also see on another site a lesser network primary hash rate at only 4430 gps. See: https://grinmint.com/pages/network-charts.html

Have a look at the secondary rate.

You can read more about Grin’s dual PoW system at What to mine? Choosing between Cuckatoo31+ and Cuckaroo29