How to calculate the "average per day" icon?

[xnf]

I try and fail to guess how does yr calculates the "average" icon.

For example, over the day there are 4. svg, 9. svg, 4. svg, 1. svg
And somehow YR decided that the sum for the day is 46.svg. How do you achieve this? Would be cool to have a corresponding function in src/index.ts :)