formulas – How to calculate probability in Google sheet based on previous years data

I was trying to get a leave taking trend and predict based on the trend that which dates are more likely to have higher number of leaves.

I have a data set of date wise leaves taken by hundreds of employees over the two years. I have calculated all week number and date name for all the leave dates. My objective is to find a pattern or trend or probability based on this data where if I input a particular date in future, it can show me how many leaves will more likely be taken on that particular date.

Here to be mentioned, as the total headcount of the employee is increasing day by day or year by year, their should be a growth factor to be considered for future prediction.

This is what I have done with the leave data:

Leave data

I have another sheet with the date wise employee headcount for the last 2 years which can be used for considering growth factor.

I am confused with the data if I can find out any trend to predict for a future date. How to use any probability functions here or any distribution functions.