Macro Optimization - Include Sum in last row of data

Dear All,

Can you please see my attached workbook and advise? I have included in the workbook the macro I'm using, which is 'imperfect' because I'm forced to make the table till the 200th row so as to include every time all the data (they usually range up to 200 rows) for the sum. Please have a look and advise how can I instruct excel to create the Sum under the last row which varies every time.

Thank you very much
ilias