Pending Order Reports vs Actual Completed Orders

We are trying to create a report which shows how many orders were in a ‘pending’ state and then failed to completed hence were never ordered.

In our accounts we have a report for all orders but we are assuming this includes the pending orders for each day as a valid sale.

example - 10 orders placed on the 1st of the month. 5 of those orders were pending and the other 5 were shipped and completed. 14 days later the 5 pending orders auto cancel and simply are removed from the order pages. however the month end sales figure still includes those transactions as sales?

surely this has an impact on the true figure for sales and VAT?

any thoughts would be much appreciated