I had some very erratic staking rewards today....did anyone else notice this...?

At any given time, I usually have 20-25 Immature VGS.  Currently, I have 218...  Very odd....  I looked through the transactions, and it appears as though each of my MNs is being awarded a "minted" reward every 10 minutes or so.

I'm not in any way complaining, just wondering what the deal is.