how do i implement the following usecase

how do i implement the following usecase

hello,

i would like to know if and how i can implement the following Usecase in zoho crm:

every month we sell to each of our thousands of customers a number of products. 
we would like to add to a Contact six new fields representing the concret number of sold products for each of the past six months:
for example:  Contact: lastMonth: 1, Month-2: 6, Month-3: 8, Month-4: 9, Month-5: 6, Month-6: 5

on every start of a new month we calculate and sync from our system the new numbers to zoho-crm.

if a Contacts' Sales of last month fall under a predefined threshold, like below the average of sales of the last six months, we would like to get a notification in zoho (that we need to talk to this customer).


my question is: can i implement something like that in zoho? and if so how?   e.g. do i need to implement this in a report and how?


thanks for any help,
florian