It looks difficult but I guess there is a formula to deal my problem:
I got a table with 3 columns.
Lets say column 1 how much hours I worked in specific day, column 2 how many costumers I served, and column 3 how much income I made.
At the top of the chart I make a Statistic formula that tells me averages, for example: how much costumers I serve in 1 hour, or how much the incomes for 1 hours, or how much is the income for 1 costumer.
So I use the COUNT formula to know the number I need to devide the sums, but what happens if I want to deal only with the last 8 lines in the table ? how can I tell the formula to check the last 8 lines which I don't know what are they, since the table gets more and more lines all the time ? is it possible ?