I'm personally surprised that blocks with lees number of transactions are getting higher fee rewards, but that's how it is.
Full blocks with fewer transactions mean wither a large number of inputs or output, since in this time no normal user is consolidating his wallet those mostly come from exchanges doing their payouts or moving their coins, and since for them time is essential and users already pay for these fees they afford to pay more. For example, one of my deposit waited for 12 hours before being confirmed at 10sat/b but in the next blocks the exchange consolidated some 30-40 deposits and moved them with a fee of 50sat/b, more than triple what it would have taken to confirm it anyway.
Now I see. Thanks for the explanation!
But still ... I just checked the last 10 blocks, and most of them have around 1 BTC or above in transaction fees. So we can't say, at least these days, that "fees are just a small part of the reward", right?
I just wanted to draw attention to this fact, because normally, indeed, the coinbase transaction amounts to more than 95% of miner's cumulative reward. But not in the days like these, look at the Fee Rewards during the December 2017 crazy racing:
Block 500900 (2017-12-25)
Block 500036 (2017-12-19)
