How to take into account the range of columns SUM calculation when creating new rows?

Question

Google Sheets

There is a standard table with working formulas.
New data is added to it by adding a new line above the current table values. I select the top row of today's values, then "Insert" → "insert row above".
There is also a line at the bottom that counts the totals of the values ​​in the columns. And for some reason, it does not take into account the range of new rows created. How would it be implemented? Every day, manually extending the range in more than 30 columns is not very desirable.
Here is an example table.

Answer 1

Here is the formula:
=AVERAGE(INDIRECT(REGEXEXTRACT(ADDRESS(ROW(); COLUMN()); "[AZ]+")&"1:"®EXEXTRACT(ADDRESS(ROW(); COLUMN()); "[AZ] +")&(ROW()-1)))
Calculates the arithmetic mean from the first row to the last one, which is immediately before the cell with the result.