Of the roughly 800 STEEM created per minute 40 go towards miners/witnesses and 40 go towards the posting and curation rewards. This represents 5% for each respective group.

This is a slight error, but perhaps quite significant and unfortunate given some of the protests we've seen about witnesses getting too large a share of rewards. In fact, of about 600 STEEM created per minute, 20 go to miners/witnesses and 40 go to authors/curators.

The reason for the error is probably that during the pure PoW phase, an extra PoW reward was given to the block producer for including the PoW. On average during pure PoW, one PoW was created per block, doubling the amount going to miners/witnesses (each PoW is worth one block reward). However, once we switched to hyrbid DPoS, only an average of one PoW is produced per round (every 21 blocks), a reduction of 95% (small enough so that I am ignoring it above).

Of the 600 STEEM created per minute roughly 3% go to miners and witnesses.

(Also, the total is reduced since liquidity rewards are disabled, but that does not affect the above numbers.)