Changing cells formatting depending of interval of time/number of years

OliverScheurich 

Hi Oliver,

I apologize. I didn't realize that you attached a file the first time you replied. I thought you were mentioning the picture I uploaded. I'm really sorry. 

Thank you It works perfectly!  

OliverScheurich  It does not necessarily answer my question. 

My question was based on the use of formulas to position the cells in the form of numbering like in RANKING. 

For example the sheet below is a results of learners who participated in a an exam. The POSITION was done manually from highest learner to the lowest one based on TTL(Total marks) for 6 subjects the learner scored. 

So, I would like to help me how can I use the formula to do that instead of manually do it. 

Hi OliverScheurich 

thank you for replying.

Yes it's the way it should be. I didn't include it for GDPR reasons, but on the left there is a column with the names of the employees.

Thanks

Luca