How to set up a heavy sieve configuration

[Petrol12]

Hello, I don't understand how to set up a heavy sieve.
I am copying recipes from 1.7.10 to 1.12.2

For example, how can I reduce the amount of flint falling out?
Maybe I don't understand how the logic works

Here's an example:

1.7.10

1.12.2

how can I subtract from 14x 13% to 6x 13%?

here is the config file 1.12.2

"entries": [
{
"name": "excompressum: compressed_block",
"metadata": "2",
"type": "list",
"rewards": [

{
"name": "minecraft: coal",
"metadata": 0,
"count": 1,
"rolls": 1,
"chance": 0.13,
"meshLevel": 3
}

And yes, sorry for the bad english, I'm from Russia
Hope for help