PD Co is deciding whether to replace its delivery vans every year or every other year. The initial cost of a van is $20,000. Maintenance costs would be nil in the first year, and $5,000 at the end of the second year. Second-hand value would fall from $10,000 to $8,000 if it held on to the van for two years instead of just one. PD Co’s cost of capital is 10%. How often should PD Co replace their vans, and what is the annual equivalent cost (‘EAC’) of that option?