The CLRC continues to increase past 20 Steem, slowly converging on (but never, I suppose, actually reaching) a maximum value.

I did some numbers a while back, so these are broad brush.

But practically if we say that a post with 250 Steem payout is pretty close to producing maximum values for each vote then:
* 0 Steem payout gives 50% of the maximum vote values
* 10 Steem payout gives 75% of the maximum
* 20 Steem payout gives 82% of the maximum
* 30 Steem payout gives 87% of the maximum
* 40 Steem payout gives 89% of the maximum
* 250 Steem payout gives 100% of the maximum

If 20 Steem payout gives votes value that are equivalent to HF20 linear then:

* 0 Steem payout gives 61% of linear
* 10 Steem payout gives 90% of linear 
* 20 Steem payout gives 100% of linear
* 30 Steem payout gives 105% of linear
* 40 Steem payout gives 108% of linear
* 250 Steem payout gives 121% of linear

It's a broad indication only; there are lots of assumptions involved.