I need some help for calculating fair usage percentage
I got $50000$ main credits to use daily and $30$ users in my website.
Each users bought different number of sub credits. For example user $1=100000$ sub credits, user $2= 50000$ sub credits, user $3=75000$ sub credits.
User with larger sub credits should get more quota usage compare to user with smaller sub credits. The percentage quota is based on their first day starting sub credits.
What formula can be use to calculate the percentage of each user fair usage for $50000$ main credits daily?