No problemQuick Base you will need to summarize these data up to another table of weeks with the key field set up be that yyyyww value.
I would use excel to import the next few years of weeks into a new table and set that field to be the key field.
Then make a relationship where one week has many shipments.
Then make summary fields on that relationship to summarize the number of trucks here and the number of trucks serviced. Then make your formula numeric field to calculate %