Those number are wrong
19.15% turn
19.57% river
34.97% turn or river
(I think you are missing that 5 cards are out)
At the flop if either are all in then you can count on no more bets on the turn.
You have to base it on what you think your opponent will do on the turn
- If you don't hit
If they bet in to you on the flop then highly likely they are going to bet turn
Even if they don't put you on a flush draw it is likely they will c bet
- If you do hit
Did your opponent put you on a flush draw?
Will they shut down if a flush hits on the turn?
You have to expect more bets if you don't hit. The question is can you expect more action if you do hit?
I like : odds
turn 4:1
turn plus river 2:1
4:1 then yes call as you are getting immediate odd
Less than 2:1 then NO as you are not even getting odds for 2 cards
If you think you can get more action if you hit then 3:1?
So assume you can get a 1/2 pot call on the turn plus river if you hit and they bet 1/2 the pot (3:1)
Ev = -1/2p + 1/5*(2*3/2)*p
= 1/10 P
-1/2p is what I had to call
1/5 is my chance of hitting on the turn
2 is the size of the pot after the after the flop
3/2 is the assumption can can get at least 1/2 pot bet called on the turn/river
Positive EV if you think you can get 1/2 pot action if you hit
So 3:1 is maybe
Note if you cannot get any action when you hit then your EV is -1/10p
But on the up side you may get more action than 1/2 p
Continue after the turn if you don't hit is another thing! One big factor is if you hit on turn you have you have two more rounds to get paid off. If they fire off 1/2 the pot again that is 1/2 of a much bigger pot and now you would need to get paid off on 1/2 of much much bigger pot on the river if you hit - not likely. And you need consider they are likely on 2 pair or trips to fire twice like that so now two of your outs are gone to a boat. Your outs are 7 of 46 = 4.6:1. At this point you hope they check to you as about all you can call is a 1/4 pot bet. I see a 1/2 pot call on the flop as trap you only use in the right situation that either gets sprung on the turn or not. If it works you don't want to just get paid off - you want it to sting. Let them think you cannot be chased off a draw with 1/2 pot bet.
Same thing with 1/2, 3/4, and full pot call on flop. If you can get that same action between the turn and river if you hit then a positive EV.
In summary
don't expect a free turn
if they bet 1/3 the pot or less then stay
if they bet the pot then leave
if they bet 1/2 the pot (or more) then be confident you can get equal action if you hit
if the board pairs then be wary
If someone bets out 1/2 the pot and you call then you have disguised your draw. If you hit the draw they are likely to bet out again. You just have to get 1/2 the new pot (double the flop pot) to call. If they shut down and check to you then chop it into 1/4 turn and 1/4 river. Out of position it is harder to get paid off so go with immediate pot odds unless you are sure you can get more action. In position with a nut flush draw and enough chips to gamble then I might call up to 1/2 pot and maybe even a full pot on a small pot. They probably have top pair, over pair, set, two pair, or just a c bet. You might still get a lot of action even if you hit. If the board pairs then hit the brakes.