Pace = 5 units completed / 16 days
Projected Yearly Outcome = pace * 365
*Note: this example is counting physical days
If you want more accurate results then you need to track this over time (months) and take the average of their paces then just simply multiply it to get the yearly estimate. Keep in mind this is just math so there is no intelligence such as Christmas and New Years where the office could be closed for a week or more. It may also make more sense to look at this in terms of working days then physical (calendar) days.